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Compliance Profile of Signed Action Receipts for AI Agents
draft-marques-asqav-compliance-receipts-04

Document Type Active Internet-Draft (individual)
Author João André Gomes Marques
Last updated 2026-05-19
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draft-marques-asqav-compliance-receipts-04
Network Working Group                                J. A. Gomes Marques
Internet-Draft                                                     Asqav
Intended status: Informational                               19 May 2026
Expires: 20 November 2026

       Compliance Profile of Signed Action Receipts for AI Agents
               draft-marques-asqav-compliance-receipts-04

Abstract

   This document defines a multi-jurisdiction compliance profile of the
   signed action receipt format used by AI agents to record machine-
   readable evidence of access-control decisions.  The profile binds
   receipt fields to two regulatory surfaces: the European Union
   obligations of Articles 12 and 26 of Regulation (EU) 2024/1689 (the
   EU AI Act) and Article 17 of Regulation (EU) 2022/2554 (DORA), and
   the United States obligations of the NIST Artificial Intelligence
   Risk Management Framework, the Colorado Artificial Intelligence Act
   (SB 24-205), the Texas Responsible AI Governance Act (HB 149), the
   New York Department of Financial Services Cybersecurity Regulation
   (23 NYCRR Part 500), the HIPAA Security Rule (45 CFR Part 164,
   Subpart C), SEC Rule 17a-4 (17 CFR 240.17a-4), and the Cyber Incident
   Reporting for Critical Infrastructure Act of 2022 (CIRCIA).  It does
   not redefine the wire format, the canonicalization transformation, or
   the signing algorithms of the underlying receipt format; it narrows
   the set of values to which the canonicalization rule is applied
   (IEEE-754 floating-point numbers MUST NOT appear in digest-covered
   fields) and tightens a small number of pre-existing wire surfaces
   under this revision (see
   Appendix "draft-marques-asqav-compliance-receipts-04").  It tightens
   a subset of the OPTIONAL fields to REQUIRED, imposes a retention
   floor, requires at least one timestamping anchor (RFC 3161 or
   OpenTimestamps; both RECOMMENDED), and adds three extension fields.
   The third, counterparty_binding, is added in this revision to provide
   cryptographic cross-agent byte-equality evidence under a compromised
   intermediary.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

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   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 20 November 2026.

Copyright Notice

   Copyright (c) 2026 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   5
     1.1.  Profile, Not Fork . . . . . . . . . . . . . . . . . . . .   5
     1.2.  Scope . . . . . . . . . . . . . . . . . . . . . . . . . .   5
   2.  Conventions and Definitions . . . . . . . . . . . . . . . . .   6
   3.  Relationship to ACTA-RECEIPTS . . . . . . . . . . . . . . . .   7
   4.  Canonicalization Scope  . . . . . . . . . . . . . . . . . . .   8
   5.  Receipt Field Profile . . . . . . . . . . . . . . . . . . . .   9
     5.1.  Common Payload Fields . . . . . . . . . . . . . . . . . .  10
       5.1.1.  type  . . . . . . . . . . . . . . . . . . . . . . . .  10
       5.1.2.  issued_at . . . . . . . . . . . . . . . . . . . . . .  10
       5.1.3.  issuer_id . . . . . . . . . . . . . . . . . . . . . .  10
       5.1.4.  payload_digest (OPTIONAL upstream, REQUIRED in this
               profile)  . . . . . . . . . . . . . . . . . . . . . .  11
       5.1.5.  action_ref (OPTIONAL upstream, REQUIRED in this
               profile)  . . . . . . . . . . . . . . . . . . . . . .  12
       5.1.6.  sandbox_state (OPTIONAL upstream, REQUIRED for
               High-Risk in this profile)  . . . . . . . . . . . . .  12
       5.1.7.  iteration_id (OPTIONAL upstream, REQUIRED for
               multi-step in this profile) . . . . . . . . . . . . .  12
     5.2.  Decision Receipt Fields (type protectmcp:decision)  . . .  12
       5.2.1.  reason (OPTIONAL upstream, REQUIRED for deny/rate_limit
               in this profile)  . . . . . . . . . . . . . . . . . .  13
       5.2.2.  policy_digest (OPTIONAL upstream, REQUIRED in this
               profile)  . . . . . . . . . . . . . . . . . . . . . .  13
       5.2.3.  scanner_decisions (OPTIONAL)  . . . . . . . . . . . .  13
     5.3.  Hash-Chain Linkage (OPTIONAL upstream, REQUIRED in this
           profile)  . . . . . . . . . . . . . . . . . . . . . . . .  14
     5.4.  Anchoring (No Upstream Equivalent)  . . . . . . . . . . .  15

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     5.5.  Extension Fields  . . . . . . . . . . . . . . . . . . . .  17
     5.6.  Counterparty Binding  . . . . . . . . . . . . . . . . . .  18
       5.6.1.  Wire Shape  . . . . . . . . . . . . . . . . . . . . .  18
       5.6.2.  Emitter Behaviour . . . . . . . . . . . . . . . . . .  20
       5.6.3.  Verifier Behaviour  . . . . . . . . . . . . . . . . .  21
   6.  European Union Bindings . . . . . . . . . . . . . . . . . . .  21
     6.1.  EU AI Act Article 12 Binding  . . . . . . . . . . . . . .  21
       6.1.1.  Article 12(1), automatic recording of events  . . . .  21
       6.1.2.  Article 12(2)(a), identifying situations that may
               result in the high-risk AI system presenting a risk
               within the meaning of Article 79(1) or in a substantial
               modification  . . . . . . . . . . . . . . . . . . . .  22
       6.1.3.  Article 12(2)(b), facilitating the post-market
               monitoring referred to in Article 72  . . . . . . . .  22
       6.1.4.  Article 12(2)(c), monitoring the operation of high-risk
               AI systems referred to in Article 26(5) . . . . . . .  22
       6.1.5.  Retention . . . . . . . . . . . . . . . . . . . . . .  22
     6.2.  EU AI Act Article 26 Binding  . . . . . . . . . . . . . .  23
       6.2.1.  Article 26(1), in accordance with the instructions for
               use . . . . . . . . . . . . . . . . . . . . . . . . .  23
       6.2.2.  Article 26(2), assign human oversight . . . . . . . .  23
       6.2.3.  Article 26(5), monitor the operation  . . . . . . . .  23
       6.2.4.  Article 26(6), keep the logs for at least six
               months  . . . . . . . . . . . . . . . . . . . . . . .  24
     6.3.  DORA Article 17 Binding . . . . . . . . . . . . . . . . .  24
       6.3.1.  Article 17(1), ICT-related incident management
               process . . . . . . . . . . . . . . . . . . . . . . .  24
       6.3.2.  Article 17(2), record all ICT-related incidents and
               significant cyber threats . . . . . . . . . . . . . .  24
       6.3.3.  Article 17(3)(b), establish procedures to identify,
               track, log, categorise and classify ICT-related
               incidents . . . . . . . . . . . . . . . . . . . . . .  24
       6.3.4.  Retention . . . . . . . . . . . . . . . . . . . . . .  24
   7.  United States Bindings  . . . . . . . . . . . . . . . . . . .  25
     7.1.  NIST AI RMF Binding . . . . . . . . . . . . . . . . . . .  25
       7.1.1.  GOVERN function . . . . . . . . . . . . . . . . . . .  25
       7.1.2.  MAP function  . . . . . . . . . . . . . . . . . . . .  26
       7.1.3.  MEASURE function  . . . . . . . . . . . . . . . . . .  26
       7.1.4.  MANAGE function . . . . . . . . . . . . . . . . . . .  26
     7.2.  Colorado AI Act (SB 24-205) Binding . . . . . . . . . . .  26
       7.2.1.  Section 6-1-1703(2), risk management policy and
               program . . . . . . . . . . . . . . . . . . . . . . .  26
       7.2.2.  Section 6-1-1703(3), impact assessment  . . . . . . .  27
       7.2.3.  Section 6-1-1703(7), notice of algorithmic
               discrimination  . . . . . . . . . . . . . . . . . . .  27
     7.3.  Texas Responsible AI Governance Act (HB 149) Binding  . .  27
       7.3.1.  Safe-harbor evidentiary support . . . . . . . . . . .  27
       7.3.2.  Prohibited-use detection  . . . . . . . . . . . . . .  27

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     7.4.  HIPAA Security Rule Binding (45 CFR Part 164, Subpart
           C)  . . . . . . . . . . . . . . . . . . . . . . . . . . .  28
       7.4.1.  45 CFR 164.312(b), audit controls . . . . . . . . . .  28
       7.4.2.  45 CFR 164.316(b)(2), six-year retention  . . . . . .  28
     7.5.  NYDFS Cybersecurity Regulation Binding (23 NYCRR Part
           500)  . . . . . . . . . . . . . . . . . . . . . . . . . .  29
       7.5.1.  23 NYCRR 500.6, audit trail . . . . . . . . . . . . .  29
       7.5.2.  23 NYCRR 500.17, notices to superintendent  . . . . .  29
       7.5.3.  23 NYCRR 500.6 retention  . . . . . . . . . . . . . .  29
     7.6.  SEC Broker-Dealer Recordkeeping Binding (17 CFR
           240.17a-4)  . . . . . . . . . . . . . . . . . . . . . . .  30
       7.6.1.  17 CFR 240.17a-4(f), electronic recordkeeping
               system  . . . . . . . . . . . . . . . . . . . . . . .  30
       7.6.2.  17 CFR 240.17a-4(a) and (b) retention . . . . . . . .  30
     7.7.  CIRCIA Binding (Cyber Incident Reporting for Critical
           Infrastructure Act of 2022) . . . . . . . . . . . . . . .  30
       7.7.1.  Covered Cyber Incident reporting support  . . . . . .  31
       7.7.2.  Records related to a Covered Cyber Incident report  .  31
   8.  Audit Pack Composition  . . . . . . . . . . . . . . . . . . .  31
   9.  Verifier Behaviour  . . . . . . . . . . . . . . . . . . . . .  33
     9.1.  Mandatory Checks  . . . . . . . . . . . . . . . . . . . .  33
     9.2.  Optional Checks . . . . . . . . . . . . . . . . . . . . .  34
     9.3.  Reporting . . . . . . . . . . . . . . . . . . . . . . . .  34
   10. Security Considerations . . . . . . . . . . . . . . . . . . .  35
     10.1.  Tamper Resistance  . . . . . . . . . . . . . . . . . . .  35
     10.2.  Chain Availability Under Single-Linear Per-Agent
             Serialization . . . . . . . . . . . . . . . . . . . . .  36
     10.3.  Key Compromise . . . . . . . . . . . . . . . . . . . . .  37
     10.4.  Retention and Long-Term Verifiability  . . . . . . . . .  37
     10.5.  Privacy  . . . . . . . . . . . . . . . . . . . . . . . .  37
     10.6.  Anchor Trust . . . . . . . . . . . . . . . . . . . . . .  38
     10.7.  Replay . . . . . . . . . . . . . . . . . . . . . . . . .  38
     10.8.  Cross-Regime Conflict  . . . . . . . . . . . . . . . . .  38
     10.9.  Algorithm Agility  . . . . . . . . . . . . . . . . . . .  39
     10.10. Issuer-Misrepresentation Residual  . . . . . . . . . . .  39
     10.11. Cross-Agent Integrity Trust Boundary . . . . . . . . . .  40
     10.12. Compromised Intermediary Between Two Honest Endpoints  .  41
   11. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  44
     11.1.  Compliance Receipt Extension Fields Registry . . . . . .  44
     11.2.  Compliance Receipt Type Namespaces Registry  . . . . . .  45
   12. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  47
   13. Normative References  . . . . . . . . . . . . . . . . . . . .  47
   14. Informative References  . . . . . . . . . . . . . . . . . . .  49
   Worked Example (Informative)  . . . . . . . . . . . . . . . . . .  52
   Change Log  . . . . . . . . . . . . . . . . . . . . . . . . . . .  54
     draft-marques-asqav-compliance-receipts-04  . . . . . . . . . .  54
     draft-marques-asqav-compliance-receipts-03  . . . . . . . . . .  60
     draft-marques-asqav-compliance-receipts-02  . . . . . . . . . .  61

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     draft-marques-asqav-compliance-receipts-01  . . . . . . . . . .  61
     draft-marques-asqav-compliance-receipts-00  . . . . . . . . . .  61
   Appendix - Capture Topologies for Compliance Receipt Emission . .  61
     In-Process SDK  . . . . . . . . . . . . . . . . . . . . . . . .  62
     Network-Layer Egress Proxy  . . . . . . . . . . . . . . . . . .  62
     Browser Extension . . . . . . . . . . . . . . . . . . . . . . .  63
     eBPF SNI Observer . . . . . . . . . . . . . . . . . . . . . . .  63
     MCP Transparent Proxy . . . . . . . . . . . . . . . . . . . . .  64
     capture_topology Vocabulary and Considerations for a Future IANA
             Registry  . . . . . . . . . . . . . . . . . . . . . . .  65
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  65

1.  Introduction

1.1.  Profile, Not Fork

   [ACTA-RECEIPTS] specifies a generic, signed receipt envelope for
   recording machine-to-machine access control decisions made by AI
   agents.  Section 2.2 of [ACTA-RECEIPTS] defines a common payload
   field set in which all fields except type, issued_at, and issuer_id
   are OPTIONAL.  Section 5.7 of [ACTA-RECEIPTS] introduces hash
   chaining (previousReceiptHash) inside an optional Commitment Mode
   extension.  [ACTA-RECEIPTS] does not define receipt retention, does
   not require timestamping anchors, and does not bind to any regulatory
   regime.

   This document is an additive overlay on [ACTA-RECEIPTS]: it
   constrains fields the upstream draft leaves OPTIONAL, fixes their
   values where regulation requires, and adds three extension fields
   with reserved names (risk_class, incident_class, and
   counterparty_binding).  A Compliance Receipt remains a conformant
   [ACTA-RECEIPTS] receipt.  Field references use upstream field names
   rather than section numbers, to reduce maintenance hazard if upstream
   re-numbers in a future revision.

1.2.  Scope

   This document fills the regulatory binding gap on two surfaces.
   Section 5 binds the receipt to European Union obligations: Article 12
   (record-keeping) and Article 26 (deployer obligations) of the EU AI
   Act, and Article 17 (ICT-related incident management) of DORA.
   Section 6 binds the receipt to United States obligations: the
   voluntary functions of the NIST AI Risk Management Framework, the
   deployer obligations of the Colorado AI Act and the Texas Responsible
   AI Governance Act, the audit-trail and incident-reporting obligations
   of NYDFS Part 500, the audit controls and documentation retention of
   the HIPAA Security Rule, the broker-dealer recordkeeping requirements
   of SEC Rule 17a-4, and the covered-incident reporting requirements of

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   CIRCIA.

   The bindings are written from the Deployer's perspective, where
   Deployer is used in the regime-specific sense (Article 3(4) of
   [EU-AI-ACT] for EU bindings; Section 6-1-1701(6) of the Colorado
   Revised Statutes for Colorado bindings).  Where another statute uses
   a different term (Provider, Financial Entity, Covered Entity for
   HIPAA, Covered Entity for NYDFS, Broker-Dealer for SEC, Covered
   Entity for CIRCIA), the binding section names the term as the source
   statute uses it.

   A verifier that implements only [ACTA-RECEIPTS] can cryptographically
   validate a profile receipt but cannot attest the additional
   compliance bindings of this document.

2.  Conventions and Definitions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   The following terms are used in this document.

   Action:  An operation performed by an AI agent that is subject to a
      policy evaluation.  Examples include a tool invocation, an
      external API call, a write to durable storage, and the issuance of
      an irreversible instruction to another system.

   Action Receipt:  A signed envelope conforming to [ACTA-RECEIPTS] that
      records the policy evaluation result for a single Action.

   Compliance Receipt:  An Action Receipt that additionally satisfies
      the requirements of this profile.

   Deployer (EU AI Act):  As defined in Article 3(4) of [EU-AI-ACT].

   Deployer (Colorado AI Act):  As defined in Section 6-1-1701(6) of the
      Colorado Revised Statutes, as enacted by [COLORADO-AI-ACT].

   High-Risk AI System (EU AI Act):  As defined in Article 6 of
      [EU-AI-ACT].

   High-Risk AI System (Colorado AI Act):  As defined in
      Section 6-1-1701(9) of the Colorado Revised Statutes, as enacted
      by [COLORADO-AI-ACT].

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   Financial Entity:  As defined in Article 2(2) of [DORA], for entities
      listed in Article 2(1).

   Covered Entity (HIPAA):  As defined in 45 CFR 160.103, namely a
      health plan, a health care clearinghouse, or a health care
      provider that transmits health information in electronic form in
      connection with a covered transaction.

   Covered Entity (NYDFS):  As defined in 23 NYCRR 500.1(e), namely any
      person operating under or required to operate under a license,
      registration, charter, certificate, permit, accreditation or
      similar authorization under the Banking Law, the Insurance Law or
      the Financial Services Law, regardless of whether the covered
      entity is also regulated by other government agencies.

   Broker-Dealer:  As defined in section 3(a)(4) and 3(a)(5) of the
      Securities Exchange Act of 1934, subject to recordkeeping under
      [SEC-17A-4].

   Covered Entity (CIRCIA):  As to be defined in the final rule
      promulgated under the Cyber Incident Reporting for Critical
      Infrastructure Act of 2022.  Pending publication of the final
      rule, the term is interpreted in accordance with the statutory
      definition at 6 U.S.C. 681 and CISA's notice of proposed
      rulemaking.

   Audit Pack:  A bundle of Compliance Receipts, the chain commitments
      that link them, the public verification keys, the trust anchor
      metadata, and the regime mapping required by Sections 5 and 6 of
      this document, packaged for delivery to a regulator or auditor.

3.  Relationship to ACTA-RECEIPTS

   This profile is an additive overlay on [ACTA-RECEIPTS].  It does not
   modify the envelope, the canonicalization rule, the signature object,
   or the algorithm registry of [ACTA-RECEIPTS].

   The following normative statements apply.

   *  Implementations of this profile MUST produce receipts that are
      cryptographically verifiable by a conformant [ACTA-RECEIPTS]
      verifier under the canonicalization rules (JCS, [RFC8785]) and the
      signature scope of [ACTA-RECEIPTS] Section 5.6.

   *  Implementations of this profile MUST NOT introduce new top-level
      fields in the signed payload that conflict with names reserved by
      [ACTA-RECEIPTS].

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   *  Implementations of this profile MAY use any signature algorithm
      permitted by [ACTA-RECEIPTS]: EdDSA (Ed25519, mandatory-to-
      implement, [RFC8032]), ES256 (ECDSA using P-256 and SHA-256,
      [RFC7518]), and ML-DSA-65 ([FIPS204]).

   *  Where [ACTA-RECEIPTS] marks a field OPTIONAL and this profile
      marks the same field REQUIRED, the stricter requirement applies to
      Compliance Receipts.

   A receipt that fails any MUST clause of this profile is not a
   Compliance Receipt.  It MAY still be a valid [ACTA-RECEIPTS] receipt.

   This profile differentiates from [ACTA-RECEIPTS] on three axes:
   mandatory hash-chain linkage (upstream Commitment Mode is OPTIONAL),
   mandatory anchoring with RFC 3161 or OpenTimestamps (both
   RECOMMENDED; upstream lists Sigstore Rekor in its Implementation
   Status appendix as an OPTIONAL temporal anchor), and a retention
   floor tied to specific regulatory articles (upstream is silent on
   retention).

4.  Canonicalization Scope

   This section is normative.  The canonicalization rule itself (JCS,
   [RFC8785]) is inherited unchanged from [ACTA-RECEIPTS]; this section
   bounds the inputs the rule is applied to, so that the cross-
   implementation byte equality on which the hash chain of Section 5.3,
   the anchor scope of Section 5.4, and the cross-agent binding of
   Section 5.6 all depend is achievable in practice.

   IEEE-754 floating-point numbers MUST NOT appear in the canonical form
   covered by a SHA-256 digest under this profile.  Callers MUST
   serialize numeric values that are not exact integers in the IEEE-754
   safe integer range (the closed interval from minus (2 to the 53 minus
   1) to plus (2 to the 53 minus 1) inclusive) either as JSON strings or
   as integer-rational pairs (numerator and denominator as JSON numbers
   within that safe integer range) before the canonicalization step.
   Rationale: Section 3.2.2.3 of [RFC8785] specifies, by reference to
   Section 7.1.12.1 of ECMA-262, a byte-stable serialization that in
   principle covers all IEEE-754 double-precision values, integer or
   fractional.  In practice, several widely deployed JSON serializers do
   not implement the ECMA-262 Number-to-String algorithm with byte
   fidelity: Python json.dumps, Go encoding/json, and Java Jackson
   (without explicit configuration) all produce different byte sequences
   from the same IEEE-754 double in documented cases (round-to-even
   ties, subnormal values, large-magnitude values requiring scientific
   notation).  Compliance and regulatory contexts (monetary amounts,
   retention thresholds, anchoring intervals) additionally prefer exact
   integer or string-encoded decimal representations because float

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   rounding loses the exact bytes that auditors quote.  This profile
   therefore shifts the canonicalization burden off implementers (who
   would otherwise have to verify ECMA-262 conformance of an underlying
   JSON library) and onto callers, who are in a better position to
   choose a portable representation for the use case at hand.  A receipt
   that carries a floating-point number in a digest-covered field is not
   guaranteed to verify across implementations even when each
   implementation independently conforms to [RFC8785], because the
   conformance burden has not been met by every mainstream JSON library.

   Tool-version-specific semantic equivalence is OUT OF SCOPE for the
   chain layer of this profile.  The chain layer guarantees byte
   equality only.  Examples of semantic equivalence that this profile
   does not assert and does not require a verifier to assert: SQL
   keyword case folding (SELECT vs select), filesystem path
   normalization (trailing slash, redundant separators, symlink
   resolution), Unicode normalization in any form (NFC, NFD, NFKC,
   NFKD); Section 3.1 of [RFC8785] requires that all components
   depending on JCS preserve Unicode string data as-is, and
   Section 3.2.2.2 of [RFC8785] serializes each code point without
   normalization, so callers MUST NOT rely on a verifier normalizing
   strings before comparison, locale-aware string collation (Turkish
   dotted-i, German sharp-s case folding, ICU collation tables), numeric
   tolerance (1.0 vs 1, 1e3 vs 1000), or URL percent-encoding choices
   below the RFC 3986 unreserved set.  Higher-level semantic equivalence
   is a per-tool concern and, where required by a regulator, MUST be
   expressed in the policy artefact resolved through policy_digest
   (Section 5.2.2) rather than in the chain.

   The chain layer of this profile answers a single question for a
   verifier or a regulator: did the same canonicalized bytes pass
   through agent X at wall-clock time T, as fixed by the anchor evidence
   of Section 5.4.  Anything beyond that question, including whether two
   byte sequences are semantically equivalent under a downstream tool,
   whether a policy update materially changed the meaning of a
   previously accepted Action, or whether a counterparty's
   interpretation of the same bytes matched the originator's, is the
   verifier's concern and is supported by the Audit Pack manifest
   (Section 8) and the verifier reporting fields of Section 9.3, not by
   the chain itself.

5.  Receipt Field Profile

   This section enumerates fields defined by [ACTA-RECEIPTS] and states
   the additional requirements that this profile places on them.  Field
   names follow [ACTA-RECEIPTS] exactly.

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   Compliance Receipts MUST use the upstream wire field name signature
   for the signature object, exactly as defined in Sections 2.1 and
   2.1.1 of [ACTA-RECEIPTS].  The keys inside that object are alg, kid,
   sig.  Implementations whose internal storage uses a different field
   name MUST translate to signature on emission and on canonicalization
   for verification; receipts that appear on the wire under any other
   top-level field name are non-conformant to [ACTA-RECEIPTS] and to
   this profile.  Anchors MUST be projected into a top-level anchors
   array with a type discriminator and a value field carrying the anchor
   bytes (base64-encoded for binary payloads).  Flat-column
   implementations MUST project on emission and Audit Pack export.

5.1.  Common Payload Fields

5.1.1.  type

   Compliance Receipts MUST set type to a value drawn from the namespace
   protectmcp:decision, protectmcp:restraint, or protectmcp:lifecycle,
   or to an extension namespace registered for use with this profile.

5.1.2.  issued_at

   REQUIRED upstream and in this profile.  The value MUST be an ISO 8601
   timestamp with an explicit timezone.  The producing system MUST
   source the value from a clock synchronized to a recognized time
   authority and MUST NOT backdate the value.  Verifiers MUST reject
   receipts whose issued_at is more than 300 seconds ahead of the
   verifier's own clock.  Verifiers MUST NOT reject a receipt solely
   because issued_at lies in the past; past skew is bounded by the
   applicable retention floor in Sections 5 and 6, not by freshness.
   Historical receipts within retention MUST verify on the same path as
   fresh ones.

5.1.3.  issuer_id

   REQUIRED upstream and in this profile.  The value MUST identify a
   legal entity, not a natural person.  Where the producing system is
   operated by a Deployer, the issuer_id MUST resolve, through the trust
   anchor metadata in the Audit Pack, to a record naming the Deployer.
   To preserve the upstream Section 2.2 invariant that issuer_id MUST
   match the kid field of the signature object, Compliance Receipts MUST
   place the same value in both issuer_id and kid; the verifier resolves
   that value to a public key through the Audit Pack trust-anchor
   metadata rather than through the well-known JWK Set endpoint or the
   RECOMMENDED sb:issuer:<base58-fingerprint> form of [ACTA-RECEIPTS]
   Section 2.1.1.  This profile thereby supersedes the upstream
   RECOMMENDED kid format for Compliance Receipts; the upstream
   RECOMMENDED format remains valid for non-Compliance receipts.

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   Implementations SHOULD use a Legal Entity Identifier (LEI) as defined
   by [ISO17442] where one is allocated to the Deployer.  Examples and
   test fixtures MUST use a placeholder whose four-character LOU prefix
   (positions 1-4) is not allocated in the GLEIF Local Operating Unit
   code list, whose positions 5-6 are the ISO 17442 reserved value 00,
   and whose two trailing characters (positions 19-20) are the ISO 7064
   mod 97-10 check digits computed over positions 1-18 (for example
   00000000000000000098, where the all-zero 18-character base produces
   the check digits 98 per the ISO 17442-1:2020 Annex A check-digit
   algorithm, which converts any letters in positions 1-18 to digits
   A=10 ... Z=35 before the mod 97-10 computation; for an all-zero base
   the conversion is a no-op); implementations MUST NOT use a real
   third-party LEI in documentation or test data.  Where no LEI is
   allocated and the Deployer is a US entity, an Employer Identification
   Number (EIN) issued by the United States Internal Revenue Service or
   a Central Index Key (CIK) issued by the United States Securities and
   Exchange Commission MAY be used, expressed as the bare numeric
   string.  Decentralized Identifiers ([W3C-DID]) MAY be used otherwise.
   Implementations MUST treat the value as opaque on verification;
   identifier resolution is out of scope for this profile.

   issuer_id values MUST be bare identifiers without a scheme prefix
   where the scheme is unambiguous from the value's syntactic form.  An
   LEI is the 20-character alphanumeric string defined by [ISO17442] and
   is self-identifying through its length and check-digit structure;
   implementations MUST emit the bare 20-character LEI without a lei: or
   other scheme prefix.  EINs and CIKs are likewise emitted as the bare
   numeric string.  Decentralized Identifiers ([W3C-DID]) carry their
   own scheme prefix (did:) as defined by the DID specification and that
   prefix is intrinsic to the identifier syntax rather than an added
   scheme tag.  The same kid-equals-issuer_id invariant requires
   signature.kid to be the bare identifier in the same form.  The worked
   example in Appendix "Worked Example (Informative)" uses the bare
   20-character placeholder LEI 00000000000000000098; conformant cloud
   emitters and SDK clients MUST match this form on the wire.

5.1.4.  payload_digest (OPTIONAL upstream, REQUIRED in this profile)

   REQUIRED for Compliance Receipts.  The value MUST follow the upstream
   object form (hash, size, optional preview) defined in Section 2.2 of
   [ACTA-RECEIPTS]; this profile does not redefine the wire shape.  The
   associated payload that this digest covers MUST be retained for the
   period mandated by the most restrictive applicable regime in Sections
   5 and 6 of this document.  Implementations MUST NOT discard the
   underlying payload while a receipt that references it is still within
   its retention window.

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5.1.5.  action_ref (OPTIONAL upstream, REQUIRED in this profile)

   REQUIRED for Compliance Receipts.  The value is a SHA-256 hash of the
   canonical Action representation as defined in [ACTA-RECEIPTS].  This
   profile uses action_ref as the primary join key for cross-engine
   reconstruction during an audit.

5.1.6.  sandbox_state (OPTIONAL upstream, REQUIRED for High-Risk in this
        profile)

   REQUIRED for receipts produced by High-Risk AI Systems under either
   [EU-AI-ACT] or [COLORADO-AI-ACT].  Upstream defines sandbox_state as
   an OS-level containment status and restricts the value to one of
   enabled, disabled, or unavailable; this profile inherits that
   enumeration unchanged.  A Deployer that operates a High-Risk AI
   System and produces a stream of receipts in which sandbox_state is
   consistently disabled SHOULD treat that stream as a finding under the
   applicable risk-management documentation requirement (Article 9 of
   [EU-AI-ACT] for the Provider's risk management system, with which a
   Deployer operating per Article 26(1) is required to be consistent;
   Section 6-1-1703(2) of the Colorado Revised Statutes) and document
   the rationale in the Audit Pack metadata.

5.1.7.  iteration_id (OPTIONAL upstream, REQUIRED for multi-step in this
        profile)

   REQUIRED for multi-step agent workflows.  The value MUST be stable
   across all receipts emitted within the same logical task or session
   so that a regulator can reconstruct the full chain of Actions.
   iteration_id is distinct from the upstream session_id field defined
   in [ACTA-RECEIPTS] Section 3.1.1, which is an opaque MCP session
   identifier.  A Compliance Receipt MAY carry both: session_id for MCP-
   session correlation and iteration_id for logical-task correlation.

5.2.  Decision Receipt Fields (type protectmcp:decision)

   The decision field value MUST be allow, deny, rate_limit, or
   observation.  Implementations using a different internal vocabulary
   (e.g. permit for allow) MUST normalise on emission and on Audit Pack
   export.  The observation value records that an Action was observed
   and the receipt was signed without any policy evaluation having taken
   place; it is the regulator-honest alternative to emitting allow when
   no policy matched, and MUST NOT appear in a receipt of type
   protectmcp:decision.  A producing system that has not evaluated a
   policy for an Action MUST either refuse to issue a Compliance Receipt
   for that Action or MUST emit the receipt with type
   protectmcp:lifecycle and decision observation; in the latter case the
   upstream policy_decision internal field, if present in the producing

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   system's internal vocabulary, takes the literal value none, which the
   emitter MUST map to observation on the wire.  Verifiers MUST reject a
   Compliance Receipt that carries decision observation together with
   type protectmcp:decision; conversely, a Compliance Receipt of type
   protectmcp:lifecycle MAY carry decision observation in addition to
   the other three vocabulary values.  The policy_digest requirement of
   Section 5.2.2 applies to observation receipts in the form of a digest
   of the producing system's "no policy matched" sentinel policy
   artefact, which the Deployer MUST retain alongside its other policy
   artefacts for the applicable retention window.

   The upstream tool_name field (REQUIRED in [ACTA-RECEIPTS]
   Section 3.1.1) is REQUIRED for Compliance Receipts of type
   protectmcp:decision.

5.2.1.  reason (OPTIONAL upstream, REQUIRED for deny/rate_limit in this
        profile)

   REQUIRED for Compliance Receipts where decision is deny or
   rate_limit.  The value MUST be a machine-readable reason code drawn
   from a vocabulary documented in the Deployer's Audit Pack metadata.

5.2.2.  policy_digest (OPTIONAL upstream, REQUIRED in this profile)

   REQUIRED for Compliance Receipts.  The value MUST be of the form
   sha256:<hex> and MUST reference a policy artefact that the Deployer
   retains for the applicable retention window.  Verifiers MUST reject
   Compliance Receipts whose policy_digest does not resolve in the Audit
   Pack.

5.2.3.  scanner_decisions (OPTIONAL)

   An OPTIONAL scanner_decisions field MAY appear in a Compliance
   Receipt of type protectmcp:decision.  When present, its value MUST be
   a JSON array of objects, where each object records the outcome of one
   content scanner plug-in that ran during policy evaluation.  Each
   object has the following members:

   *  scanner_id (string, REQUIRED): stable identifier for the scanner
      plug-in (e.g. presidio, llm-guard, cedar).

   *  scanner_version (string, REQUIRED): vendor-reported version string
      for the scanner instance that produced the outcome.

   *  scanner_decision (string, REQUIRED): one of allow, scan_blocked,
      or observation; matches the wire vocabulary of the parent decision
      field where applicable.

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   *  latency_ms (integer, OPTIONAL): wall-clock time in milliseconds
      the scanner took to produce the outcome.

   *  signature (string, OPTIONAL): vendor-supplied detached signature
      over the scanner outcome, used by Deployers that require non-
      repudiation per scanner instance.

   The field is OPTIONAL because Deployers running a single in-process
   scanner (the common starter deployment) gain no auditing value from
   echoing the outcome and would only pay an envelope-size cost.  The
   per-scanner signature member is OPTIONAL for the same reason:
   cryptographic non-repudiation across multiple independent scanner
   vendors is an Enterprise-tier concern and not mandated at this
   profile revision.  Verifiers MUST tolerate the absence of
   scanner_decisions and MUST NOT infer that no scanners ran from its
   absence.

5.3.  Hash-Chain Linkage (OPTIONAL upstream, REQUIRED in this profile)

   Upstream Commitment Mode introduces previousReceiptHash as part of an
   optional extension.  This profile makes the linkage REQUIRED.
   Implementations MUST emit a previousReceiptHash field, populated per
   the digest-scope rule of Section 5.7 of [ACTA-RECEIPTS]: the
   lowercase hex encoding of SHA-256 over the canonical signing-input
   bytes of the immediately prior receipt emitted by the same issuer_id,
   where the canonical signing-input bytes are the JCS-canonical
   serialization ([RFC8785]) of the predecessor's signed payload object
   (the same bytes the predecessor's cryptographic signature covers),
   NOT the envelope object that additionally includes the signature or
   anchors top-level keys.  The first receipt in a chain MUST set this
   field to the all-zero SHA-256 value (this profile's stipulation;
   [ACTA-RECEIPTS] Section 5.7 specifies only the digest scope of
   subsequent links).  JSON key is the literal previousReceiptHash
   (camelCase, case-sensitive); snake_case aliases MUST NOT appear on
   the wire.

   Rationale for the payload-bytes (signing-input) digest scope rather
   than the envelope-including-signature digest scope: the chain layer's
   purpose is to make after-the-fact alteration of the predecessor's
   signed content detectable, and the predecessor's signed content is
   exactly the bytes its signature covers (the canonical payload
   object).  Digesting those bytes binds the chain to what A actually
   attested to, is recomputable offline from the predecessor's payload
   alone, and matches Section 5.7 of [ACTA-RECEIPTS].  The chain does
   not need to bind the predecessor's signature value directly because
   the predecessor's signature is verified independently under
   Section 9.1, and cross-agent envelope integrity (where binding the
   peer's signature value matters) is the role of counterparty_binding

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   per Section 5.6, which digests at the envelope-including-signature
   scope precisely because the peer signature is the load-bearing
   artefact in the cross-agent case.  Implementations that previously
   digested the envelope-including-signature object MUST migrate to the
   signing-input scope before emitting chained receipts under this
   profile; verifiers MUST recompute under the signing-input scope when
   checking previousReceiptHash.

   Each issuer MUST maintain a single linear per-agent chain.  When one
   agent identity emits receipts from multiple concurrent execution
   paths (for example parallel tool calls dispatched within a single
   agent loop, or fan-out work performed by a thread pool inside one
   issuer), the issuer MUST serialize emission through a single
   predecessor pointer at a time: each newly emitted receipt's
   previousReceiptHash MUST resolve to the SHA-256(JCS(receipt)) of the
   immediately prior receipt emitted by that same issuer_id, taken in
   emission order, regardless of which concurrent execution path
   produced it.  Parallel sub-chains within one agent identity (for
   example, a per-receipt chain_id discriminator that would partition
   one issuer's stream into multiple independently advancing chains) are
   NOT defined by this profile.  An issuer that requires parallel sub-
   chains MUST express each parallel path as a distinct agent identity,
   with its own issuer_id value, its own signing key, and its own per-
   agent chain rooted at the all-zero SHA-256 genesis value.  Rationale:
   deterministic verification of the chain segment covering an audit
   window, as required by the regime bindings of Sections 5 and 6 (in
   particular Section 6.3.2, Section 7.5.1, and Section 7.6.1), depends
   on a single linear total order over the receipts emitted under each
   agent identity; a verifier reconstructing the chain from a regulator-
   supplied issuer_id needs that ordering to be well-defined without
   out-of-band metadata.

5.4.  Anchoring (No Upstream Equivalent)

   [ACTA-RECEIPTS] lists Sigstore Rekor in its Implementation Status
   appendix as an OPTIONAL temporal anchor.  This profile imposes a
   normative anchoring requirement.

   Compliance Receipts MUST be anchored.  An anchor is an [RFC3161]
   timestamp token covering the signed envelope, an [OPENTIMESTAMPS]
   commitment covering the envelope, or both; implementations SHOULD
   emit both forms.  For both anchor types, the bytes committed are SHA-
   256(JCS(envelope_minus_anchors)), where envelope_minus_anchors is the
   wire envelope object with the anchors top-level key removed prior to
   canonicalization, leaving the two-key object {payload, signature}.
   The anchors key MUST be removed from the object, not set to null or
   to an empty array; these produce different JCS output and break
   interoperability (mirroring the upstream Section 5.6 stripping rule).

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   The anchor thereby binds payload and signature without being self-
   referential.  The anchor evidence MUST be retained alongside the
   receipt for the applicable retention window.  Verifiers MUST reject
   Compliance Receipts that lack at least one valid anchor.

   An anchor MAY be attached after issuance if the receipt is persisted
   with an unambiguous pending marker and the anchor lands within a
   documented bound.  For [OPENTIMESTAMPS], this profile imposes a 7-day
   deadline; this is a profile-imposed bound, not a property of the
   OpenTimestamps protocol, whose calendar-to-block upgrade time depends
   on the calendar operator's publication interval.  [RFC3161] tokens
   MUST be obtained synchronously.  A verifier MUST treat a pending
   receipt as non-conformant once the bound elapses.

   The anchor MAY cover an aggregate of receipts (for example, a Merkle
   root over a batch) rather than each receipt individually, provided
   that the inclusion proof linking the receipt to the aggregate is
   retained alongside the receipt and the aggregate anchor.

   Where the anchor type is [RFC3161], the full TimeStampResp DER bytes
   MUST be retained, sufficient for offline verification by a holder
   with access to the TSA's published public key.  Time-stamp tokens
   carrying ESSCertIDv2 per [RFC5816] MUST be accepted by Compliance
   Verifiers.  Where the anchor type is [OPENTIMESTAMPS], the upgrade
   from the initial calendar attestation to the Bitcoin block
   attestation MUST be completed within the 7-day profile-imposed bound,
   and the upgraded proof MUST be retained for the applicable retention
   window per the second paragraph of this section.

   Each entry in the top-level anchors array is an object with the
   following members.

   type:  REQUIRED string discriminator.  MUST be one of rfc3161 or
      opentimestamps.

   value:  REQUIRED on every anchor entry.  The anchor token bytes,
      base64-encoded.  For rfc3161 the value is the base64 encoding of
      the full TimeStampResp DER bytes (sufficient for offline
      cryptographic re-verification by a holder with access to the TSA's
      published public key).  For opentimestamps the value is the base64
      encoding of the OpenTimestamps proof blob (the .ots
      serialization).  A verifier MUST cryptographically re-verify the
      anchor against the signed envelope using these bytes per
      Section 9.1; anchor entries served without value MUST NOT be
      reported as anchor_valid_*=true.

   status:  OPTIONAL informational string.  When present, MUST be one of

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      anchored (the anchor has reached its final attestation state: an
      [RFC3161] token has been obtained, or an [OPENTIMESTAMPS]
      commitment has upgraded to its Bitcoin block attestation), pending
      (the anchor has been requested but the final attestation state has
      not yet been reached, e.g. an OpenTimestamps commitment that has
      been submitted to a calendar but has not yet upgraded to a Bitcoin
      block within the 7-day bound of this section), or failed (the
      anchor submission was attempted and did not produce a usable
      attestation, e.g. a TSA returned an error response or an
      OpenTimestamps calendar refused the commitment). status is
      operational metadata; a verifier MUST NOT derive cryptographic
      validity from status alone, and MUST always re-verify the value
      bytes per Section 9.1.

   bitcoin_block:  OPTIONAL informational string.  The Bitcoin block
      hash at which an [OPENTIMESTAMPS] commitment was anchored.
      Present only on entries with type=opentimestamps and
      status=anchored; absent on rfc3161 entries and on pending or
      failed OpenTimestamps entries. bitcoin_block is operational
      metadata; a verifier MUST NOT derive cryptographic validity from
      bitcoin_block alone, and MUST always re-verify the value bytes
      against the OpenTimestamps proof per Section 9.1.

5.5.  Extension Fields

   This profile defines three extension fields that MAY appear in the
   signed payload alongside the fields defined by [ACTA-RECEIPTS].  The
   first two, risk_class and incident_class, are defined in this
   section.  The third, counterparty_binding, is defined in Section 5.6.

   risk_class:  A vocabulary term identifying the risk classification of
      the Action under the Deployer's risk management documentation.
      The vocabulary MUST be referenced in the Audit Pack metadata.
      Where the Deployer operates under [EU-AI-ACT], the documentation
      is the Provider's Article 9 risk management system as referenced
      via the instructions for use under Article 26(1); where the
      Deployer operates under [COLORADO-AI-ACT], the documentation is
      the Section 6-1-1703(2) risk management policy and program.

   incident_class:  A vocabulary term identifying the incident
      classification of the Action under the applicable regime: an ICT-
      related incident under [DORA], with classification criteria in
      [REG-2024-1772] and the canonical reporting enumeration of Annex
      II data glossary, field 3.23 (Type of the incident) of
      [REG-2025-302] (verifiers MUST resolve the canonical values from
      the regulation directly); a Cybersecurity Event under 23 NYCRR
      500.1(f) (or, where the Section 500.17(a) reporting threshold is
      met, a Cybersecurity Incident under 23 NYCRR 500.1(g)) for Covered

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      Entities of [NYDFS-500]; a Covered Cyber Incident under [CIRCIA]
      once the final rule takes effect; or a security incident under 45
      CFR 164.304 for Covered Entities of [HIPAA-SECURITY].
      Implementations MAY refine the set, provided the flattened mapping
      in the Audit Pack manifest (Section 8) projects each refinement to
      the applicable canonical category for each in-scope regime.

   risk_class MUST be encoded as a JSON string. incident_class MUST be
   encoded as a JSON string drawn from the canonical vocabulary
   referenced in the Audit Pack, OR as a JSON array of such strings to
   preserve cross-regime classification (for example, a single Action
   that is both a DORA ICT-related incident and a CIRCIA Covered Cyber
   Incident, or both a NYDFS Cybersecurity Incident and a CIRCIA Covered
   Cyber Incident).  Both extension fields appear inside the signed
   payload object and are therefore covered by the upstream Section 5.6
   signature scope.  Both fields are OPTIONAL at the syntactic level but
   MAY be REQUIRED by the regime bindings in Sections 5 and 6 of this
   document.

   Implementations MAY define additional extension fields.  Such fields
   MUST NOT collide with names defined by [ACTA-RECEIPTS] or by this
   document.  Implementations defining extension fields SHOULD register
   them in the registry described in Section 11.

5.6.  Counterparty Binding

   This section is normative. counterparty_binding is an in-payload
   object an acknowledging agent ("B") emits to carry a cryptographic
   digest of the full signed envelope of an originating agent ("A").  It
   provides cross-agent byte-equality evidence when a shared
   intermediary sits between two honest agents and the per-agent hash
   chains of Section 5.3 validate independently regardless of whether
   B's observed bytes equal A's signed bytes. action_ref is a
   correlation anchor, not a cryptographic binding ([ACTA-RECEIPTS]
   Section 2.2); counterparty_binding moves the evidence onto B's own
   COSE or JWS signature, which the verifier already trusts.

5.6.1.  Wire Shape

   The field MUST appear inside the signed payload object.  It MUST NOT
   appear in unprotected COSE or JWS header parameters, or in
   external_aad per [RFC9052] Section 4.3 when the receipt is used for
   audit (external_aad is permissible only in transport-optimized modes
   out of scope for Compliance Receipts).  For COSE-framed receipts the
   field sits inside the COSE_Sign1 or COSE_Sign payload per [RFC9052]
   Section 4.1; for JWS-framed receipts it is a top-level claim per
   [RFC7515].

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   The field is an object with the following members.

   envelope_hash:  REQUIRED string.  Base64-encoded SHA-256 digest
      computed over A's entire serialized signed envelope, including A's
      signature bytes.  The digest input is framing-specific.  JSON-
      framed (this profile's default for receipts that are not
      transported under COSE or JWS, and mandatory-to-implement for any
      conformant Compliance Receipt implementation): the JCS-canonical
      UTF-8 byte sequence of A's signed envelope JSON object per
      [RFC8785], where the envelope is the three-key object {"payload":
      <signed payload object>, "signature": <signature object with alg,
      kid, sig members>, "anchors": <array of anchor objects,
      OPTIONAL>}. The payload object carries the signed fields A emitted
      (including type, issuer_id, issued_at, action_ref, payload_digest,
      previousReceiptHash, decision, and any extension fields under
      Section 5.5); the signature object carries the algorithm
      identifier, key identifier, and base64- or base64url-encoded
      signature bytes exactly as A emitted them.  B MUST NOT re-
      canonicalize A's payload or strip the anchors array before
      computing the digest.  COSE-framed: the full COSE_Sign1 or
      COSE_Sign byte string per [RFC8949] Section 4.2 (deterministic
      encoding).  JWS-framed: the full JWS Compact Serialization
      (header.payload.signature) after payload canonicalization per
      [RFC8785].  The digest algorithm is SHA-256 (mandatory-to-
      implement); the encoding MUST be standard base64 per [RFC4648]
      Section 4 on emission, OR base64url per Section 5 where the
      surrounding transport requires URL-safe encoding; verifiers MUST
      accept both alphabets and MUST normalise to a single alphabet
      (typically standard base64) before byte-comparing to a recomputed
      value.  Including A's signature in the digest scope binds the
      signed-over content of A's receipt at the envelope level and
      prevents an intermediary that re-signs A's claims with a different
      key from escaping detection.  The framing in which A's envelope
      was emitted MUST be preserved through B's binding: the value of
      envelope_hash is framing-specific because JCS-canonical JSON
      (UTF-16 code-unit lexicographic key ordering per [RFC8785]), COSE
      deterministic encoding (length-then-byte map-key ordering per
      [RFC8949] Section 4.2), and JWS Compact Serialization with JCS-
      canonical payload (UTF-16 code-unit lexicographic ordering per
      [RFC8785]) produce different byte sequences from the same semantic
      payload-and-signature, and the three framings therefore yield
      different envelope_hash values for the same underlying receipt.  A
      transcoding intermediary that re-frames A's envelope (JSON to
      COSE, COSE to JWS, or any other pairing) changes the digest input
      and MUST be treated as a tampering event by the verifier;
      verifiers MUST NOT reframe an envelope before recomputing
      envelope_hash.  Future revisions MAY extend to additional digest
      algorithms drawn from the [ACTA-RECEIPTS] digest algorithm

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      registry; implementations that require algorithm negotiation
      SHOULD carry the algorithm identifier out of band in the Audit
      Pack manifest rather than in the wire field.

   receipt_ref:  REQUIRED opaque content-addressed locator the verifier
      resolves through the Audit Pack or a Deployer-published index to
      A's full signed envelope.  The value is an opaque string from the
      verifier's perspective; producers MAY use any stable identifier
      scheme (URI, content-addressed digest, opaque database id) so long
      as the Audit Pack resolution layer returns the correct envelope
      bytes.  Future profiles (for example, a SCITT-style inclusion-
      proof profile under [ACTA-RECEIPTS] Section 4.2 extension
      semantics) MAY layer on this field.

   expect_ack_from:  OPTIONAL string.  The expected acknowledging-party
      identifier, expressed as a kid or issuer_id value matching the
      same bare-identifier form required by Section 5.1.3.  When
      present, the field declares which acknowledging party A or the
      producer expects to sign over this receipt's bytes; a verifier MAY
      use expect_ack_from to cross-check that the acknowledging
      receipt's kid matches the expected identifier.  Verifiers MUST NOT
      reject solely on absence of an acknowledging receipt; absence is a
      liveness-loss signal observable through Audit Pack metadata rather
      than a non-conformance condition on the current receipt.

   transport_label:  OPTIONAL string (mcp, bus, orchestrator, http).
      Operational only; verifiers MUST NOT derive trust from this label.

   "counterparty_binding": {
     "envelope_hash": "bDqg...5PE=",
     "receipt_ref": "asqav-receipt://org/123/agent_A/seq/4811",
     "expect_ack_from": "00000000000000000098",
     "transport_label": "mcp"
   }

   The COSE form follows the same member set under deterministic CBOR
   map ordering per [RFC8949] Section 4.2.

5.6.2.  Emitter Behaviour

   B SHOULD emit counterparty_binding when any of the following hold:
   A's signing request flagged the action as requiring acknowledgment
   (for example, by populating an expect_ack_from list); the Deployer's
   risk management documentation requires bilateral byte-binding; or B
   is operating under the guidance of Section 10.11.  B MUST compute
   envelope_hash over the exact byte stream it received and accepted,
   not over a re-canonicalization at B; re-canonicalizing at B masks
   intermediary tampering whenever the tampered bytes canonicalize to

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   the same payload object, which is the threat case this section
   addresses.  Where one acknowledgment receipt confirms envelopes from
   N originators, the field MAY be an array of objects; pairwise
   bindings cannot prove all N originators emitted identical bytes (see
   Section 10.10).

5.6.3.  Verifier Behaviour

   A Compliance Verifier processing a receipt carrying
   counterparty_binding MUST, in addition to Section 9.1, resolve
   receipt_ref through the Audit Pack or a Deployer-published index to
   A's full signed envelope, recompute the SHA-256 digest of that
   envelope under the scope rule of Section 5.6.1, base64-encode the
   result, and compare to envelope_hash.  A non-resolving receipt_ref or
   a digest mismatch MUST cause the acknowledging receipt to be reported
   non-conformant; liveness loss at A MUST NOT be silently treated as
   success.  Where expect_ack_from is present, the verifier SHOULD
   additionally check that the acknowledging receipt's signature.kid
   matches the declared identifier (under the bare-identifier form
   required by Section 5.1.3); mismatch SHOULD be reported as an axis
   flag rather than as outright non-conformance because the field is
   OPTIONAL.

   The Deployer or Audit Pack producer MUST retain A's signed envelope
   for at least as long as any acknowledging receipt binding it remains
   within retention under Sections 5 and 6.  For chains of three or more
   agents, this profile defaults to pairwise bindings; multi-signer co-
   presence under [RFC9052] Section 4.1 is OPTIONAL, and verifiers MUST
   NOT treat a co-signed envelope as a substitute for a pairwise binding
   chain.

6.  European Union Bindings

6.1.  EU AI Act Article 12 Binding

   Each subsection cites the operative phrase of Article 12 and binds it
   to the receipt field that satisfies it.

6.1.1.  Article 12(1), automatic recording of events

   Article 12(1) requires High-Risk AI Systems to technically allow for
   the automatic recording of events (logs) over the lifetime of the
   system.  The signed-receipt format provides one mechanism that
   satisfies that logging capability; alternative mechanisms remain
   valid.  Where this profile is chosen, a Compliance Receipt SHOULD be
   produced for every Action against an external resource, and a
   configuration change that disables receipt generation SHOULD be
   recorded as a protectmcp:lifecycle Compliance Receipt.

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   Implementations MAY emit at finer or coarser granularity so long as
   the log set, taken together, satisfies Article 12(2)(a) through (c).

6.1.2.  Article 12(2)(a), identifying situations that may result in the
        high-risk AI system presenting a risk within the meaning of
        Article 79(1) or in a substantial modification

   The combination of type, decision, reason, and policy_digest MUST be
   sufficient for an auditor to identify, by query alone, receipts that
   correspond to risk situations enumerated in the Deployer's risk
   management documentation.  Where the Deployer classifies an Action as
   risk-bearing, the receipt MUST carry a risk_class extension field.

6.1.3.  Article 12(2)(b), facilitating the post-market monitoring
        referred to in Article 72

   The hash-chain linkage required by Section 5.3 satisfies post-market
   monitoring traceability.  The chain head MUST be made available to
   the Provider and to the competent authority on request.

6.1.4.  Article 12(2)(c), monitoring the operation of high-risk AI
        systems referred to in Article 26(5)

   Any change to the policy artefact referenced by policy_digest MUST
   produce a new digest.  A change in policy_digest between two
   otherwise-comparable Actions may be examined by the Deployer or by a
   regulator as a candidate substantial-modification event under Article
   43, and MUST be retained at least as long as the longest receipt in
   the chain that references either digest.

6.1.5.  Retention

   Article 12 itself sets no retention period; the operative deployer
   floor is Article 26(6) ("at least six months").  The parallel
   provider floor in Article 19(1) sets the same six-month minimum on
   Providers; this profile's retention bindings are written from the
   Deployer perspective, and a Provider that wishes to use Compliance
   Receipts as its Article 19(1) record SHOULD adopt the Deployer floor
   explicitly through a separate Provider-role binding (deferred to a
   future revision).

   EU AI Act Article 26(6) requires six months of logs (interpreted as
   184 days when expressed as a day-count floor for hash-chain anchoring
   intervals).  The normative requirement on Compliance Receipts is:
   implementations MUST retain receipts until the later of (a) the day
   six calendar months after the date of the Action, computed calendar-
   arithmetically per [ISO8601-2] duration arithmetic, and (b) any
   longer Union or national law floor.  The six-month period is read

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   calendar-month-wise (the receipt expiry day is the same day-of-month
   six months later, with end-of-month rollover where the target month
   is shorter), not as a fixed day count.

   The 184-day figure (the maximum number of days in any rolling six-
   calendar-month window, worst case Aug-Jan, 31+30+31+30+31+31) is
   informative only; it expresses a safe day-count floor for hash-chain
   anchoring intervals and Audit Pack export windows where calendar-
   arithmetic is impractical at the producer layer.  A Deployer that
   retains receipts strictly under the calendar-month rule above
   satisfies Article 26(6); a Deployer that uses 184 days as an internal
   day-count overestimate also satisfies it.  The 183-day pick mentioned
   in earlier revisions is not endorsed by this profile: under a rolling
   six-calendar-month window 1 August to 31 January spans 184 days and
   183 days is one day short.  Where the Deployer is also a Financial
   Entity, the sectoral floor in Section 6.3.4 applies.

6.2.  EU AI Act Article 26 Binding

6.2.1.  Article 26(1), in accordance with the instructions for use

   policy_digest MUST resolve through Section 8 to a retained artefact
   (machine check).  The Deployer SHOULD demonstrate consistency with
   the Provider's instructions for use (process check).  Inability to
   perform the machine check is presumed non-compliance.

6.2.2.  Article 26(2), assign human oversight

   For any Action whose decision is allow and which the Deployer's risk
   management documentation marks as requiring human oversight, the
   Deployer MUST ensure that the receipt is either reviewed by a
   designated natural person within the period required by national law,
   or that a follow-on protectmcp:lifecycle Compliance Receipt records
   the absence of such review with a reason code.  Both records MUST
   themselves be Compliance Receipts.  This profile addresses the
   trigger and record of oversight; the competence, training, authority,
   and necessary support of the reviewer required by Article 26(2)
   remain the Deployer's separate responsibility.

6.2.3.  Article 26(5), monitor the operation

   A Deployer MUST be able to produce an Audit Pack covering any
   contiguous time window since the High-Risk AI System became
   operational.

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6.2.4.  Article 26(6), keep the logs for at least six months

   Compliance Receipts under this binding MUST be retained for at least
   the period stated in Section 6.1.5.  Where the Deployer is also a
   Financial Entity, the longer sectoral floor in Section 6.3.4 applies.

6.3.  DORA Article 17 Binding

6.3.1.  Article 17(1), ICT-related incident management process

   A Compliance Receipt produced inside a Financial Entity's ICT
   environment may serve as the canonical record of an Action that
   triggered an ICT-related incident. action_ref MUST be carried into
   the Financial Entity's incident workflow as the primary correlation
   key.

6.3.2.  Article 17(2), record all ICT-related incidents and significant
        cyber threats

   The hash chain required by Section 5.3 supports the recording
   obligation of Article 17(2) by making after-the-fact alteration of
   recorded incidents detectable.  The Financial Entity MUST be able to
   produce, on request, the chain segment covering the period of an
   incident, together with the anchor evidence that fixes the chain to
   wall-clock time.

6.3.3.  Article 17(3)(b), establish procedures to identify, track, log,
        categorise and classify ICT-related incidents

   For Actions identified as part of an ICT-related incident, the
   producing system MUST emit incident_class.  The classification
   criteria are those set out in Article 18(1) of [DORA], with further
   specification in [REG-2024-1772].  The canonical reporting
   enumeration to which incident_class flattens is bound by Annex II
   field 3.23 of [REG-2025-302] (see Section 5.5).  Implementations MUST
   publish a flattened mapping in the Audit Pack manifest as required by
   Section 5.5.

6.3.4.  Retention

   Article 17 of [DORA] does not itself set a uniform numeric retention
   floor.  The five-year (1827-day) figure used by this profile derives
   from sectoral instruments that overlap DORA-scoped Financial
   Entities.  Investment firms keep records of all services, activities
   and transactions under Article 16(6) of [MIFID2], with Article 72 and
   Annex I of [REG-2017-565] fixing the form and content of those
   records.  The explicit five-year retention period in [MIFID2] is set
   by Article 16(7) for records of telephone conversations and

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   electronic communications, kept for a period of five years and, where
   requested by the competent authority, for a period of up to seven
   years.

   Records of customer due diligence and of transactions under Article
   40 of [AMLD] are kept for five years after the end of the business
   relationship.  The AMLD record-keeping regime is superseded, in
   respect of record retention, by Article 77 of [AMLR] from 10 July
   2027, which preserves the five-year floor and adds a case-by-case
   extension up to a further five years where the competent authority so
   requires.  Implementations operating across the AMLD-to-AMLR
   transition MUST satisfy whichever instrument is in force on the date
   of the Action.

   Compliance Receipts MUST be retained for the period required by
   applicable Union or national law; where a sectoral floor applies,
   retention MUST equal or exceed the longest applicable floor.  Absent
   a more specific rule, this profile RECOMMENDS 1827 days from the date
   of the Action (the worst-case rolling five-calendar-year window
   contains two leap days, so 1827 days satisfies "five years"
   regardless of the calendar years over which the window falls).
   Anchor evidence MUST be retained for the same period.  Verification
   keys whose lifetime expires within the retention window MUST have
   their public components retained so that historical signatures remain
   verifiable.

7.  United States Bindings

7.1.  NIST AI RMF Binding

   [NIST-AI-RMF] is a voluntary framework.  Adoption of this profile, on
   its own, does not establish conformity with the AI RMF; it provides a
   tamper-evident receipt substrate that an AI RMF program can use as
   evidence under the MEASURE function and as a structured input to the
   GOVERN, MAP, and MANAGE functions.  [NIST-GENAI-PROFILE] applies the
   AI RMF functions to generative AI; the profile bindings below apply
   to generative and non-generative AI agent deployments alike unless
   explicitly noted.

7.1.1.  GOVERN function

   The GOVERN function requires that organizations document AI policies
   and procedures.  The combination of policy_digest and the Audit Pack
   manifest provides a machine-readable binding between every Action and
   the policy artefact in force at the time of the Action.  A change to
   the policy artefact MUST produce a new policy_digest value (per
   Section 5.2.2); the Audit Pack therefore records every policy change
   in a tamper-evident manner.

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7.1.2.  MAP function

   The MAP function requires that the context, capabilities, and risks
   of an AI system be characterised.  The combination of type,
   tool_name, action_ref, and iteration_id SHOULD be sufficient for an
   auditor to reconstruct the operational context of any Action without
   dereferencing the underlying payload.

7.1.3.  MEASURE function

   The MEASURE function requires that AI risks and impacts be analysed
   and tracked over time.  The hash-chain linkage required by
   Section 5.3 provides tamper-evident continuity of the receipt stream
   over the AI system's operational lifetime, satisfying the
   traceability prerequisite of MEASURE.

7.1.4.  MANAGE function

   The MANAGE function requires that AI risks be prioritised and acted
   upon based on projected impact.  The risk_class extension field
   carries the Deployer's risk classification of the Action; together
   with decision, reason, and policy_digest, it supports prioritisation
   and incident response without requiring the verifier to re-derive
   risk from the underlying payload.

7.2.  Colorado AI Act (SB 24-205) Binding

   [COLORADO-AI-ACT] imposes deployer obligations effective June 30,
   2026 (per Senate Bill 25B-004, which postponed the original February
   1, 2026 effective date).  The Act regulates the deployment of High-
   Risk AI Systems and the prevention of algorithmic discrimination.

7.2.1.  Section 6-1-1703(2), risk management policy and program

   Section 6-1-1703(2) requires deployers to implement a risk management
   policy and program for the High-Risk AI System. policy_digest MUST
   resolve through Section 8 to the deployer's risk management policy
   artefact in force at the time of the Action.  Where the Deployer
   classifies an Action as risk-bearing under that policy, the receipt
   MUST carry a risk_class extension field.

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7.2.2.  Section 6-1-1703(3), impact assessment

   Section 6-1-1703(3) requires deployers to complete an impact
   assessment annually and within 90 days after any intentional and
   substantial modification of the High-Risk AI System.  The combination
   of type, policy_digest, and previousReceiptHash MUST be sufficient
   for an auditor to identify, by query alone, the receipts that span
   the period covered by an impact assessment, including any policy
   changes within that period.

7.2.3.  Section 6-1-1703(7), notice of algorithmic discrimination

   Where a Deployer determines that a High-Risk AI System has caused or
   is reasonably likely to have caused algorithmic discrimination, the
   producing system SHOULD record that determination as a
   protectmcp:lifecycle Compliance Receipt naming the determination, the
   affected receipts by action_ref, and the policy or risk-management
   response with a reason code.

7.3.  Texas Responsible AI Governance Act (HB 149) Binding

   [TEXAS-TRAIGA] takes effect January 1, 2026.  The Act adopts an
   intent-based liability framework for the development and deployment
   of AI systems and provides a safe harbor at Section 552.105(e)(2)(D)
   of the Texas Business and Commerce Code for organisations that
   substantially comply with the most recent version of
   [NIST-GENAI-PROFILE], or another nationally or internationally
   recognized risk management framework for AI systems, and operate an
   internal review process.

7.3.1.  Safe-harbor evidentiary support

   Where a Deployer relies on the safe-harbor provision of HB 149 by
   substantially complying with [NIST-GENAI-PROFILE], the Audit Pack MAY
   be presented as evidence of that compliance.  The bindings of
   Section 7.1 apply, with the additional Generative AI Profile bindings
   of [NIST-GENAI-PROFILE].

7.3.2.  Prohibited-use detection

   Receipts whose decision is deny with a reason code drawn from a
   vocabulary documenting the Act's prohibited-use categories under
   Section 552.052 of the Texas Business and Commerce Code added by HB
   149 (incitement or encouragement of physical self-harm including
   suicide, harm to another person, or engagement in criminal activity)
   MUST be retained for the period stated in Section 7.4.2 or the longer
   period required by Texas law, whichever is greater.

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7.4.  HIPAA Security Rule Binding (45 CFR Part 164, Subpart C)

   [HIPAA-SECURITY] applies to Covered Entities (HIPAA) that handle
   electronic protected health information.  The bindings below apply
   only to receipts whose underlying Actions reference electronic
   protected health information.

7.4.1.  45 CFR 164.312(b), audit controls

   45 CFR 164.312(b) requires implementation of "hardware, software,
   and/or procedural mechanisms that record and examine activity in
   information systems that contain or use electronic protected health
   information".  The combination of type, action_ref, tool_name, and
   the hash-chain linkage required by Section 5.3 satisfies the
   recording requirement; the verification rules of Section 9.1 satisfy
   the examination requirement.

7.4.2.  45 CFR 164.316(b)(2), six-year retention

   45 CFR 164.316(b)(2) (and in particular the subparagraph
   164.316(b)(2)(i)) requires that the documentation required by 45 CFR
   164.316(b)(1) be retained "for 6 years from the date of its creation
   or the date when it last was in effect, whichever is later".  The
   audit-log content produced under 45 CFR 164.312(b) is not itself
   documentation required by 164.316(b)(1); the Security Rule does not
   set an explicit retention floor for individual audit-log records.  By
   analogy with the six-year floor that 164.316(b)(2) places on the
   policies and procedures that govern audit-log generation, this
   profile applies the same six-year floor to Compliance Receipts whose
   underlying Actions reference electronic protected health information.

   Records covered by the HIPAA Security Rule audit-trail retention MUST
   be retained for six years from the date of creation or the date when
   last in effect, whichever is later, per 45 CFR 164.316(b)(2).  This
   profile expresses that floor as 2192 days from the later of (a) the
   date of the Action and (b) the date the policy artefact referenced by
   policy_digest ceased to be in effect: 2192 is the maximum number of
   days in any rolling six-calendar-year window (worst case spans two
   leap days, e.g. 2024-2030 contains February 29 of 2024 and 2028,
   yielding 6*365+2 = 2192 days).  The six-year analogy floor is
   grounded in 164.316(b)(2); a Covered Entity that retains receipts
   strictly under 164.316(b)(2)(i) bound only to the policy artefact's
   creation-or-cessation date MAY do so when no longer audit-log floor
   is established by separate Union, state, or sectoral law.
   Verification keys whose lifetime expires within the retention window
   MUST have their public components retained so that historical
   signatures remain verifiable.

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7.5.  NYDFS Cybersecurity Regulation Binding (23 NYCRR Part 500)

   [NYDFS-500] applies to Covered Entities (NYDFS) operating under New
   York Banking, Insurance, or Financial Services Law. The bindings
   below apply only to receipts produced by such Covered Entities.

7.5.1.  23 NYCRR 500.6, audit trail

   23 NYCRR 500.6(a) requires Covered Entities to securely maintain
   systems that, to the extent applicable and based on its risk
   assessment, (1) are designed to reconstruct material financial
   transactions, and (2) include audit trails designed to detect and
   respond to cybersecurity events that have a reasonable likelihood of
   materially harming any material part of the normal operations of the
   Covered Entity.  The hash chain required by Section 5.3 together with
   the anchor evidence required by Section 5.4 satisfies the tamper-
   evidence prerequisite of the audit-trail obligation.

7.5.2.  23 NYCRR 500.17, notices to superintendent

   23 NYCRR 500.17(a)(1) requires that "Each covered entity shall notify
   the superintendent electronically in the form set forth on the
   department's website as promptly as possible but in no event later
   than 72 hours after determining that a cybersecurity incident has
   occurred at the covered entity, its affiliates, or a third-party
   service provider."  The reporting trigger is a Cybersecurity Incident
   under 23 NYCRR 500.1(g), not any Cybersecurity Event under 500.1(f).
   For Actions identified as part of such an Incident, the producing
   system MUST emit incident_class with a value indicating Cybersecurity
   Incident under 23 NYCRR 500.1(g), and the Covered Entity MUST be able
   to produce, on request, the chain segment covering the period of the
   Incident together with the anchor evidence that fixes the chain to
   wall-clock time.

7.5.3.  23 NYCRR 500.6 retention

   23 NYCRR 500.6(b) requires that "Each Covered Entity shall maintain
   records required by this section for not fewer than five years."  The
   five-year floor applies uniformly to records required by paragraph
   (a)(1) (designed to reconstruct material financial transactions) and
   to records required by paragraph (a)(2) (audit trails designed to
   detect and respond to cybersecurity events that have a reasonable
   likelihood of materially harming any material part of the normal
   operations of the Covered Entity).  Compliance Receipts produced
   under this binding MUST be retained for at least 1827 days from the
   date of the Action (the worst-case rolling five-calendar-year window
   contains two leap days).

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7.6.  SEC Broker-Dealer Recordkeeping Binding (17 CFR 240.17a-4)

   [SEC-17A-4] applies to Broker-Dealers, Security-Based Swap Dealers,
   and Major Security-Based Swap Participants.  The bindings below apply
   only to receipts produced inside such entities.

7.6.1.  17 CFR 240.17a-4(f), electronic recordkeeping system

   The November 3, 2022 amendments to 17 CFR 240.17a-4 (compliance date
   May 3, 2023) added an audit-trail alternative to the prior write-
   once-read-many (WORM) electronic recordkeeping requirement.  The
   audit-trail alternative requires that the electronic recordkeeping
   system permit the recreation of an original record if it is modified
   or deleted.  The hash-chain linkage required by Section 5.3 together
   with the retention rule in Section 7.6.2 and the anchor evidence
   required by Section 5.4 satisfies the audit-trail alternative when
   the Compliance Receipt is the system-of-record for a regulated
   record.

7.6.2.  17 CFR 240.17a-4(a) and (b) retention

   17 CFR 240.17a-4(a) requires preservation of certain records for not
   less than 6 years, the first two years in an easily accessible place.
   17 CFR 240.17a-4(b) requires preservation of a different list of
   records for not less than three years, the first two years in an
   easily accessible place.  Compliance Receipts that constitute or
   support a record listed in 17 CFR 240.17a-4(a) MUST be retained for
   at least 2192 days from the date of the Action, applying the same
   six-year worst-case methodology as Section 7.4.2; receipts that
   constitute or support a record listed only in 17 CFR 240.17a-4(b)
   MUST be retained for at least 1096 days from the date of the Action
   (the worst-case rolling three-calendar-year window contains one leap
   day).  Where both apply, the longer period applies.

7.7.  CIRCIA Binding (Cyber Incident Reporting for Critical
      Infrastructure Act of 2022)

   [CIRCIA] requires Covered Entities (CIRCIA) to report Covered Cyber
   Incidents to the Cybersecurity and Infrastructure Security Agency
   within 72 hours of reasonable belief that the incident has occurred,
   and to report ransom payments within 24 hours.  The reporting
   obligations take effect upon publication of the final rule.  Pending
   publication, the bindings below apply on a voluntary basis.

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7.7.1.  Covered Cyber Incident reporting support

   For Actions identified as part of a Covered Cyber Incident, the
   producing system MUST emit incident_class with a value indicating
   Covered Cyber Incident under [CIRCIA].  The Covered Entity MUST be
   able to produce, on request, the chain segment covering the period of
   the incident together with the anchor evidence that fixes the chain
   to wall-clock time.

7.7.2.  Records related to a Covered Cyber Incident report

   Section 2242(a)(4) of the Homeland Security Act of 2002, as enacted
   by [CIRCIA] and codified at 6 U.S.C. 681b(a)(4), requires Covered
   Entities to preserve data relevant to a Covered Cyber Incident or
   ransom payment in accordance with procedures established in the final
   rule.  CISA's notice of proposed rulemaking at 89 FR 23644 (April 4,
   2024), proposed Section 226.13(c), proposes a preservation period of
   not less than two years measured from the submission of the most
   recently required CIRCIA report (or the date that submission would
   have been required absent a preservation exception under proposed
   Section 226.4(a)); this profile uses that proposed floor pending
   publication of the final rule.

   Records covered by CIRCIA preservation MUST be retained for two years
   from the submission of the most recently required CIRCIA report under
   6 U.S.C. 681b(c)(2).  Compliance Receipts that are referenced in a
   CIRCIA report or that the Covered Entity reasonably anticipates will
   be so referenced MUST be retained for the longer of (a) the period
   established by the final rule and (b) two years from the submission
   of the most recently required CIRCIA report (or the date that
   submission would have been required absent a preservation exception),
   per proposed Section 226.13(c) of the CIRCIA NPRM at 89 FR 23644
   (April 4, 2024).  Covered Entities MUST NOT measure the retention
   floor from the date of the underlying Action; an Action detected and
   reported months later carries a preservation window that runs forward
   from the report submission date.

8.  Audit Pack Composition

   This section is informative.  It describes the contents of an Audit
   Pack as introduced in Section 2.

   An Audit Pack contains the following items.

   *  The set of Compliance Receipts covered by the requested time
      window, in the canonical envelope form defined by [ACTA-RECEIPTS].

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   *  The chain commitments that link the receipts: for each receipt,
      the value of previousReceiptHash and the recomputed digest of the
      predecessor envelope.

   *  The anchor evidence: [RFC3161] tokens, OpenTimestamps proofs, or
      both.  Each anchor item MUST be associated, by hash, with the
      receipt or aggregate it covers.

   *  The trust anchor metadata that identifies the Deployer or other
      regulated entity associated with each issuer_id value.

   *  The verification key material for every kid value present, in a
      form that does not require online retrieval.

   *  Vocabularies referenced by reason, risk_class, incident_class, and
      extension fields, embedded as JSON arrays with a stable
      identifier.  The Audit Pack MUST expose a digest-resolution
      facility that, given a policy_digest, returns the retained
      artefact.

   *  A regime mapping document that names which receipts the producer
      asserts as evidence under any of the regimes addressed by Sections
      5 and 6 of this document (EU AI Act Article 12, EU AI Act Article
      26, DORA Article 17, NIST AI RMF, Colorado AI Act, Texas
      Responsible AI Governance Act, NYDFS Part 500, HIPAA Security
      Rule, SEC Rule 17a-4, CIRCIA).

   *  The chain heads valid at the start and end of the time window,
      signed by the Deployer or other regulated entity.

   An Audit Pack MUST itself be signed per the [ACTA-RECEIPTS] algorithm
   registry.  The manifest MUST include bundle_digest, bundle_signature,
   bundle_public_key, and algorithm_registry_version.

   The following manifest-level fields SHOULD appear on an Audit Pack
   bundle when the underlying receipt stream exposes the corresponding
   semantics.  Each is informative and does not alter the wire shape of
   individual receipts.

   regime_mapping_disclaimer:  String emitted on bundles whose per-
      receipt regime predicates derive from mapping logic the original
      producing system did not sign.  The value identifies the producer
      of the mapping, the document version under which it was computed,
      and a disclaimer that the regime-satisfaction flags are advisory
      and remain subject to the verifier's own check against Sections 5
      and 6.

   stale_pending:  Boolean flag set per bundle entry whose anchor

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      evidence is still pending after the bound of Section 5.4 (7 days
      for OpenTimestamps; synchronous for RFC 3161).  When true, the
      bundled receipt is non-conformant per Section 5.4, and a
      Compliance Verifier consumes the flag to drive anchor_valid_*
      false in its per-axis report (see Section 9.3).  A verify endpoint
      over the same bundle SHOULD surface stale_pending in its response.

9.  Verifier Behaviour

   A verifier conformant to this profile is referred to as a Compliance
   Verifier.

9.1.  Mandatory Checks

   A Compliance Verifier MUST perform all of the following checks before
   treating a receipt as a Compliance Receipt.

   *  Verify the signature using the algorithm declared in
      signature.alg, in accordance with [ACTA-RECEIPTS].

   *  Resolve the verification key through one of the key-distribution
      mechanisms described in Section 4.3 of [ACTA-RECEIPTS] (well-known
      JWK Set or out-of-band distribution), or through Audit Pack trust-
      anchor metadata.  The verifier MUST NOT trust a verification key
      embedded in the receipt envelope.

   *  Verify that all fields marked REQUIRED by Section 5 are present
      and well-formed.

   *  Verify the hash-chain linkage by recomputing SHA-256 over the
      canonical signing-input bytes of the immediately preceding receipt
      (the JCS-canonical serialization of the predecessor's signed
      payload object, per Section 5.3) and comparing the lowercase hex
      encoding to previousReceiptHash.

   *  Verify at least one anchor: an [RFC3161] token, an
      [OPENTIMESTAMPS] commitment, or both.  The anchor MUST cover the
      signed envelope as it appears in the receipt.  The verifier MUST
      cryptographically re-verify the anchor against the signed
      envelope; presence of anchor metadata without a successful
      cryptographic check MUST NOT yield "valid".

   *  Verify the future-skew bound on issued_at per Section 5.1.2.  Past
      skew MUST NOT cause non-conformance when the receipt is within
      retention.

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   *  Verify that policy_digest resolves through Section 8.  A digest
      computed over a nonced or otherwise mixed-input form (for example,
      SHA-256(nonce || JCS(artefact))) MUST NOT be treated as
      policy_digest; the digest scope is the canonical form of the
      artefact alone.  The verifier MUST recompute SHA-256 over the
      canonical form of the resolved artefact as documented in the Audit
      Pack manifest, and compare; for JSON artefacts the canonical form
      is JCS per [RFC8785].

   A receipt that fails any of these checks MUST be reported as non-
   conformant.

9.2.  Optional Checks

   A Compliance Verifier MAY additionally perform any of the following.

   *  Cross-check the issuer_id against an external registry (LEI, EIN,
      CIK, NPI, GLEIF, or a Deployer-published list).

   *  Resolve the policy artefact referenced by policy_digest and
      compare it to a Provider-supplied or Deployer-supplied reference
      policy.

   *  Recompute the chain head and compare it to a Deployer-published
      value.

   *  Validate incident_class (each element if encoded as an array) and
      risk_class extension values against the vocabularies referenced in
      the Audit Pack.

9.3.  Reporting

   A Compliance Verifier SHOULD produce a structured per-receipt report
   that names the regime bindings the receipt satisfies and the outcome
   of the per-axis checks the verifier performed.  The following fields
   SHOULD be emitted; the axes are independent and consumers MUST NOT
   collapse them into a single boolean before display.

   regimes_satisfied:  Array of short stable regime identifiers drawn
      from the regimes listed in Section 8 (for example eu_ai_act, dora,
      nist_ai_rmf, colorado_ai, texas_traiga, hipaa_security, nydfs_500,
      sec_17a4a, sec_17a4b, circia).  The set is open-ended; consumers
      MUST treat unknown identifiers as informational.  Where this field
      is inherited from a producer-side mapping in the bundle, the
      bundle-level regime_mapping_disclaimer of Section 8 applies.

   anchor_valid_ots:  Boolean. true when an [OPENTIMESTAMPS] anchor is

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      present, has upgraded to the Bitcoin block attestation within the
      7-day bound of Section 5.4, and re-verifies cryptographically
      against the signed envelope; otherwise false (including the case
      where the only present anchor is RFC 3161).

   anchor_valid_rfc3161:  Boolean. true when an [RFC3161] token is
      present, carries an ESSCertIDv2 per [RFC5816] where required, and
      re-verifies cryptographically against the signed envelope;
      otherwise false.

   policy_digest_resolved:  Boolean. true when policy_digest resolved to
      a retained artefact whose JCS-canonical SHA-256 matches the
      receipt value, per Section 9.1; false on absence, resolution
      failure, or digest mismatch.

   duplicate_emission_candidate:  Boolean. true when at least one other
      receipt sharing action_ref and issuer_id has been observed in the
      same Audit Pack or in a verifier-maintained index; otherwise
      false.  The axis is informational; this profile does not require
      verifiers to maintain a cross-receipt index.  An absent index MUST
      report false rather than omit the axis, so consumers learn "no
      duplicate" from the value and learn "axis unknown" only from the
      verifier's documented capability set.

   A receipt may carry anchor_valid_ots=true and
   anchor_valid_rfc3161=false (or vice versa) and still satisfy the
   mandatory anchor check of Section 5.4, which requires only one valid
   anchor.  Where a receipt carries counterparty_binding per
   Section 5.6, the verifier SHOULD additionally emit the outcome of the
   check of Section 5.6.3; this profile reserves a stable field
   identifier for that axis pending implementation experience.

10.  Security Considerations

   This profile inherits all of the security considerations of
   [ACTA-RECEIPTS].  The following considerations are specific to the
   compliance binding.

10.1.  Tamper Resistance

   The hash-chain linkage required by Section 5.3 provides tamper-
   evidence at the chain level.  An adversary who removes a receipt from
   the middle of the chain MUST recompute and re-sign every subsequent
   envelope.  The anchor evidence required by Section 5.4 binds segments
   of the chain to wall-clock time, raising the cost of a re-signing
   attack.

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   Implementations SHOULD anchor at intervals no longer than 24 hours.
   Implementations operating under DORA Article 17, 23 NYCRR 500.17, or
   [CIRCIA] SHOULD anchor at intervals no longer than one hour, given
   the four-hour initial-notice deadline (with 72-hour intermediate-
   report and one-month final-report bounds) per DORA Article 17 and the
   RTS in [REG-2025-301], the 72-hour notification clock under 23 NYCRR
   500.17, and the 72-hour CIRCIA covered-cyber-incident reporting
   deadline that will apply once the CIRCIA final rule takes effect.

   A deployment that uses only the signature, without chain linkage and
   anchoring, can be rolled back by an insider with control of the
   signing key for the period between the deletion and the next anchor.
   The MUST clauses of Section 5.3 and Section 5.4 close that window.

10.2.  Chain Availability Under Single-Linear Per-Agent Serialization

   This section is informative.  The single-linear per-agent chain
   requirement of Section 5.3 serializes receipt emission for a given
   issuer_id through a single predecessor pointer.  A denial-of-service
   against the predecessor pointer (database row lock contention,
   network partition between the emitter and the predecessor store, slow
   IO, or an adversary deliberately holding the chain-tail lock)
   therefore bounds the per-agent emission throughput, because every new
   receipt MUST resolve the digest of the immediately prior receipt
   before it can be linked.  A partial-write failure between
   predecessor-pointer commit and signature commit can additionally
   produce chain-head ambiguity if not handled defensively.

   Issuers SHOULD use a bounded predecessor-lookup timeout (operator-
   tuned, typically on the order of seconds rather than tens of seconds)
   and SHOULD emit a structured audit event with type
   protectmcp:lifecycle and a stable reason code (RECOMMENDED:
   chain_emission_blocked) when the timeout fires, rather than silently
   dropping the receipt or stalling caller threads.  Issuers SHOULD
   additionally document a chain-head recovery procedure for crashed
   emitters: on restart, the issuer re-reads the predecessor row,
   verifies that no orphan signature exists for the next sequence
   position, and resumes emission.  Operators that require parallel per-
   issuer throughput beyond what a single linear chain sustains MUST use
   distinct issuer_id values per parallel path, with separate signing
   keys and chains rooted at the all-zero genesis value, per the rule in
   Section 5.3.

   The threat profile here is availability, not confidentiality or
   integrity: a successful chain-availability attack delays or drops
   emission, but it cannot tamper with already-emitted receipts (those
   are protected by Section 10.1) and it cannot forge receipts (those
   are protected by Section 10.3).  The chain_emission_blocked lifecycle

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   receipt is itself a Compliance Receipt and therefore links into the
   chain once emission resumes, so the gap is detectable rather than
   silent.

10.3.  Key Compromise

   A Compliance Receipt is only as trustworthy as the key that signed
   it.  On suspected compromise of an issuer key, the Deployer MUST
   publish a revocation notice that names the key, the time of suspected
   compromise, and the chain head at that time.  Receipts signed by the
   compromised key after the named time MUST NOT be treated as
   Compliance Receipts.

   Verifiers MUST consult revocation metadata supplied with the Audit
   Pack and MUST reject Compliance Receipts whose signing key was
   revoked at or before issued_at.

10.4.  Retention and Long-Term Verifiability

   The longest retention floor in this profile is 2192 days (six
   calendar years), set by Section 7.4 and Section 7.6; the EU side has
   a parallel five-year (1827-day) floor under Section 6.3.  Both exceed
   the typical operational crypto-period of a signing key under
   recommended key-management practice.  Implementations SHOULD use ML-
   DSA-65 from the [ACTA-RECEIPTS] algorithm registry ([FIPS204]) for
   receipts expected to be verified after the cryptographic lifetime of
   classical signature schemes ends.  Implementations MUST retain public
   key material for the entire retention window.

10.5.  Privacy

   [ACTA-RECEIPTS] prohibits the inclusion of raw prompts, tool
   arguments, and credentials in the signed payload.  This profile
   extends that prohibition to the extension fields defined in this
   document.  The risk_class and incident_class values MUST be drawn
   from controlled vocabularies and MUST NOT carry free-text personal
   data.

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   Where the underlying Action references a data subject, the
   payload_digest field MUST cover the data; the data itself MUST be
   held in a separate store that respects the data subject's rights
   under applicable law (including but not limited to the General Data
   Protection Regulation for EU data subjects, the California Consumer
   Privacy Act and Virginia Consumer Data Protection Act for the
   corresponding US states, and the HIPAA Privacy Rule where electronic
   protected health information is involved).  A request for erasure
   that is granted under applicable data protection law MUST be
   reflected by deletion of the referenced payload, not by deletion of
   the receipt; the receipt remains as evidence that an Action occurred
   and was governed by a named policy at a named time.

10.6.  Anchor Trust

   The trust assumptions of an anchor depend on the anchor type.
   [RFC3161] timestamp tokens depend on the trust placed in the named
   Time Stamping Authority.  OpenTimestamps commitments depend on the
   inclusion of the commitment in a public Bitcoin block.  A Compliance
   Verifier SHOULD treat the simultaneous presence of both anchor types
   as stronger evidence than the presence of only one.

10.7.  Replay

   A Compliance Receipt is bound to a single Action via action_ref.
   Replay of a Compliance Receipt against a different Action is
   detectable by action_ref mismatch.  The 300-second issued_at skew
   bound stated in Section 5.1.2 limits the window in which a freshly-
   replayed receipt can be presented as recent.

   Where the verifier supports it, two receipts sharing action_ref and
   issuer_id SHOULD be flagged as a candidate duplicate-emission event
   for human review.  This profile does not require verifiers to
   maintain a cross-receipt index; deployers needing duplicate-emission
   detection should arrange it at the Audit Pack production layer.

10.8.  Cross-Regime Conflict

   Where the same Action is in scope of more than one regime addressed
   by this document, the producing system MUST satisfy the union of the
   applicable requirements.  Where a SHOULD clause in one regime
   conflicts with a MUST clause in another, the MUST clause prevails.
   Where two MUST clauses conflict, the producing system MUST refuse to
   issue the receipt and MUST log the refusal as a protectmcp:lifecycle
   Compliance Receipt.

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10.9.  Algorithm Agility

   This profile inherits its algorithm registry from [ACTA-RECEIPTS].
   Implementations MUST treat the verification of a historical receipt
   according to the algorithm registry that was in force at issued_at,
   not the registry in force at the time of verification, provided that
   the signing key was not revoked.

10.10.  Issuer-Misrepresentation Residual

   Per-agent hash chains under Section 5.3 detect tampering inside a
   single issuer's stream but not the cross-agent attack in which a
   compromised intermediary silently swaps payload bytes between two
   honest agents.  Both per-agent chains validate; action_ref is a
   correlation anchor, not a cryptographic binding ([ACTA-RECEIPTS]
   Section 2.2).  Under -03, a regulator obtains no cryptographic answer
   to "did the acknowledging agent acknowledge the bytes the originating
   agent actually sent".  This revision introduces counterparty_binding
   (Section 5.6) as the partial mitigation; the following residuals
   remain.

   *  Endpoint collusion.  If both signing keys are compromised by the
      same attacker, the attacker produces a coordinated forgery; no
      signature scheme defends against this case.

   *  Intermediary holds the originating agent's key.  In hosted-agent
      deployments where the intermediary possesses the originating
      agent's private key, it can sign anything as either party.  Remote
      attestation of key origin is the appropriate countermeasure and is
      out of scope here.

   *  Originator offline at verification time.  Section 5.6.3 requires
      the originating envelope to be retrievable; if unpublished,
      offline, or rate-limited, the binding becomes unverifiable
      (liveness loss, observable as failure).

   *  Fan-out witness gap.  When an originator broadcasts to N
      acknowledgers, each emits an independent pairwise binding; none
      witnesses any other.  Append-only log profiles (future SCITT-style
      transparency) are deferred to a later revision.

   *  Key rotation orphan.  If the originating agent rotates keys after
      emission but before an acknowledger binds it, the storage
      obligation of Section 5.6.3 still requires the old envelope to
      remain retrievable; if retention discipline fails, the binding
      orphans.

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   *  Privacy of envelope hashes. envelope_hash is computed over the
      full signed bytes including A's signature; an observer of B's
      receipt learns a stable identifier for A's exact action and
      therefore can correlate B's behaviour across receipts even when
      A's payload is otherwise confidential.  Where this correlation is
      unacceptable, a commitment scheme (for example, HMAC over the
      envelope with a per-counterparty key disclosed only to the
      verifier) is appropriate; this profile does not specify one.

   *  Real-time prevention. counterparty_binding is detective, not
      preventive: B has already accepted the bytes by the time the
      binding is signed.  Verifiers detect tampering only at audit time;
      the in-flight bytes were not blocked.  Where prevention is
      required, transport-level integrity per Section 10.11 is the
      appropriate primitive in addition to (not instead of) this
      profile.

   *  Payload-content semantics.  The binding proves byte equality, not
      semantic equality.  An intermediary that re-encodes A's bytes into
      a different but JCS-equivalent canonical form is detected (the
      SHA-256 differs); an intermediary that swaps A's bytes for
      entirely different bytes that B's policy happens to interpret as
      semantically equivalent is detected too.  But an intermediary that
      swaps A's bytes for an A-signed REPLAY of a prior valid envelope
      from A is not detected by this binding alone; replay protection
      requires that the verifier also check action_ref and
      previousReceiptHash uniqueness within the chain segment.

10.11.  Cross-Agent Integrity Trust Boundary

   This section is informative.  It records operator guidance for cases
   where channel-level protection is the only available defence and
   counterparty_binding per Section 5.6 has not yet been adopted by both
   endpoints.  For channels between named principals, implementers
   SHOULD secure the channel using mutually authenticated TLS 1.3 per
   [RFC8446]; MAY use the tls-exporter channel binding per [RFC9266]
   derived via [RFC5705] where higher channel uniqueness is required;
   and MAY layer HTTP Message Signatures per [RFC9421] where
   intermediaries perform legitimate transformations.

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   Operators MUST NOT interpret transport-layer security alone as
   evidence of cross-agent byte equality.  Only counterparty_binding
   produces application-layer, signed, replay-after-the-fact evidence
   answering that question.  Topologies where the intermediary
   terminates TLS (CDN edges, MCP servers, message buses, orchestrators)
   defeat transport-layer integrity against the threat case of
   Section 10.10; in those topologies counterparty_binding is the only
   defence this profile offers, and the absence of channel-binding
   evidence in the Audit Pack SHOULD be documented as a known residual.

10.12.  Compromised Intermediary Between Two Honest Endpoints

   This section is informative.  Where an Action travels from a sending
   agent A to a receiving agent B through one or more intermediary
   processes M, and where M is compromised in such a way that M presents
   byte sequence X to A and a different byte sequence X' to B, neither
   A's nor B's cryptographic signature detects the divergence in
   isolation: each endpoint signs the bytes it observed, and each
   endpoint's per-agent hash chain per Section 5.3 remains internally
   valid.  Under draft-marques-asqav-compliance-receipts-03 the only
   available cross-agent primitive was action_ref as a SHA-256 join key
   per Section 5.1.5; both A's chain and B's chain remained valid in
   isolation, and divergence was only recoverable through a regulator-
   driven post-hoc comparison of the two chains.

   counterparty_binding introduced in Section 5.6 closes the case where
   M silently swaps bytes between two honest endpoints A and B.  In this
   revision (-04), B's acknowledging receipt is REQUIRED to carry an
   envelope_hash computed over the exact byte stream B received (SHA-
   256(A's envelope) under the digest-scope rule of Section 5.6.1).  A
   verifier resolves receipt_ref to A's stored envelope, recomputes the
   digest, and compares; a mismatch indicates that the bytes B signed
   are not the bytes A signed, and the acknowledging receipt MUST be
   reported non-conformant per Section 5.6.3.  The binding is detective
   rather than preventive: it does not stop M from performing the swap
   in flight, but it produces signed, replay-after-the-fact evidence
   that the swap occurred.

   The following residuals remain and are not closed by
   counterparty_binding alone.  The list is intentionally honest about
   the audit-time, not sign-time, nature of the detective evidence: a
   verifier resolves receipt_ref to A's retained envelope and recomputes
   the digest at audit time, so any residual reasoning that depends on
   "A is not in the loop at sign time" is rhetorical, not load-bearing.

   *  Collusion of M and B.  If M and B are jointly compromised, M swaps
      the bytes in flight and B issues an acknowledging receipt carrying
      an envelope_hash computed over the altered bytes that B signs as

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      if they were A's.  Under counterparty_binding the audit-time
      verifier resolves receipt_ref to A's retained envelope and
      recomputes the digest, so the binding is reported non-conformant
      when A's storage is honest and reachable; M+B collusion alone does
      NOT silently succeed.  M+B collusion silently succeeds only when
      the collusion ALSO extends to corrupting A's retained envelope,
      suppressing A's chain segment, or making A's storage unreachable
      to the auditor; that is, the true residual is M+B+(A's-storage
      compromise or unavailability).  Operator mitigation: anchor A's
      chain on independent witnesses (combined [RFC3161] +
      [OPENTIMESTAMPS] anchors per Section 5.4, and OPTIONAL deployer-
      operated transparency logs) so that A's anchored chain-segment
      digests are independently recoverable from public evidence;
      regulator-side comparison of A's anchored chain against B's stored
      chain detects the divergence even when A's local storage is
      impeached.

   *  Collusion of M and A.  If M and A are jointly compromised, A signs
      a fabricated envelope at M's direction and M relays it to B; B
      verifies M's relay normally, B's counterparty_binding correctly
      digests the bytes A signed, A's per-agent chain validates, and B's
      per-agent chain validates.  Every cryptographic invariant in this
      profile holds because the binding correctly attests that the bytes
      B received were the bytes A signed; the fraud is in A's intent,
      not in any byte mismatch.  This residual is fundamentally outside
      the receipt model's threat surface: no application-layer
      cryptographic primitive in this profile distinguishes a fraudulent
      A-signed envelope from an honest A-signed envelope when M is also
      colluding to corroborate plausibility (relay logs, timestamping,
      message ordering).  Operator mitigation: separation of duties
      between issuer (A) and intermediary (M) so that the same operator
      cannot control both signing keys and relay logs; anchor evidence
      on independent witnesses under different trust roots so that an
      attacker controlling A and M still cannot retroactively coordinate
      anchor inclusion across uncolluding timestamping authorities; out-
      of-band attestation by the regulator or auditor of A's operational
      context (provenance, code signing, runtime attestation) where the
      policy regime authorises it.

   *  Compromise of B itself.  A B that has been compromised (private
      key extraction, supply-chain compromise, or insider operation) can
      sign any envelope_hash the attacker chooses; counterparty_binding
      proves only that the signing key acknowledged some bytes, not that
      those bytes match what an honest B would have observed.

   *  Loss of A's stored envelope. counterparty_binding requires the
      verifier to resolve receipt_ref to A's full signed envelope; if
      A's chain segment is unavailable (retention discipline failure,

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      key rotation orphan, deliberate withholding), the binding becomes
      unverifiable and the receipt is reported non-conformant on
      liveness grounds rather than on byte-equality grounds.  An
      adversary who can arrange A-envelope unavailability and then re-
      emit colluding bytes can degrade the binding from a byte-equality
      check to a liveness-loss flag.

   Operators concerned about these residuals in the absence of single-
   point cryptographic defence SHOULD:

   *  Anchor receipts to multiple independent witnesses.  Where both
      [RFC3161] and [OPENTIMESTAMPS] anchors are present per
      Section 5.4, a coordinated M-B collusion attack must also induce
      both timestamping authorities to anchor the colluding bytes within
      the operator's anchor interval, raising the conjunction-cost of
      the attack.  Operators MAY add further anchors (e.g. a Deployer-
      operated transparency log or a witness service) without changing
      the wire format defined here.

   *  Use side-by-side chain comparison under regulator subpoena.  The
      audit-trail alternative semantics established for SEC 17a-4
      recordkeeping (see Section 7.6.1) and the post-market surveillance
      regime of EU AI Act Articles 12 and 26 (see Section 6.1 and
      Section 6.2) authorise the regulator to compel both A's and B's
      Audit Packs and to reconstruct the relay by joining on action_ref
      per Section 5.1.5. counterparty_binding reduces the regulator's
      workload from "compare both chains and detect divergence" to
      "verify B's bound digest against A's stored envelope"; the
      underlying subpoena-and-compare workflow remains the regulator's
      ultimate authority and remains operative when the binding is
      unverifiable.

   *  Document M's relay logs out-of-band.  Where the intermediary M is
      identifiable (a named MCP server, message bus, orchestrator, or
      relay), the operator SHOULD require M to produce signed relay logs
      covering the time window of the Action and SHOULD submit those
      logs to the same Audit Pack production layer as A's and B's
      chains.  Out-of-band relay logs do not require a wire-format
      change in this profile; they are operational evidence that
      complements counterparty_binding rather than replacing it.

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   The worst-case latency to detection for an M-only compromise (not M-B
   collusion) is bounded by the anchor interval recommended in
   Section 10.1: 24 hours by default, one hour for Deployers operating
   under [DORA] Article 17, 23 NYCRR 500.17, or [CIRCIA].  After the
   next anchor commits, the divergence between A's anchored chain
   segment and the digest carried in B's counterparty_binding is
   permanently recoverable from the anchored evidence alone, without
   trust in M.

11.  IANA Considerations

   This document requests two new IANA registries to support stable,
   machine-checkable extensions to the Compliance Receipt format.

11.1.  Compliance Receipt Extension Fields Registry

   IANA is requested to create a new registry titled "Compliance Receipt
   Extension Fields" under a new "Compliance Receipts" registry group.

   This registry covers both signed-payload fields and envelope-level
   fields (siblings of payload and signature); each entry's Description
   identifies which.

   Each entry contains:

   *  Field Name: a JSON object key, lowercase ASCII letters, digits,
      and underscore.

   *  Description: a one-line summary of the field's purpose.

   *  Reference: the document that defines the field's semantics.

   *  Vocabulary: a URL or registry pointer for the controlled
      vocabulary that field values are drawn from, or "free-form" if
      none.

   The registration policy is Specification Required, per [RFC8126].
   The Designated Expert(s) SHOULD verify that the field name does not
   collide with any field defined by [ACTA-RECEIPTS], that the Reference
   is a stable, dereferenceable specification, and that the Vocabulary
   is documented sufficiently for an independent verifier to validate
   values.

   Initial registry contents (each entry labelled with Scope to
   disambiguate signed-payload fields from envelope-level fields per the
   registry description above):

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   *  risk_class - Scope: signed-payload - Risk classification term
      under the Deployer's risk management documentation - This document
      - Vocabulary referenced in Audit Pack metadata.

   *  incident_class - Scope: signed-payload - Incident classification
      term spanning DORA Article 18(1) (with further specification in
      [REG-2024-1772] and the canonical reporting enumeration of Annex
      II field 3.23 of [REG-2025-302]), 23 NYCRR 500.1 Cybersecurity
      Event/Incident, [CIRCIA] Covered Cyber Incident, and HIPAA
      security incident under 45 CFR 164.304 - This document - Audit
      Pack metadata.

   *  counterparty_binding - Scope: signed-payload - Signed-payload
      object carrying a base64-encoded SHA-256 digest (envelope_hash) of
      a peer agent's full signed envelope including signature bytes, a
      resolvable opaque locator (receipt_ref), an OPTIONAL expected-
      acknowledger identifier (expect_ack_from), and an OPTIONAL
      operational transport_label; see Section 5.6 for the full member
      set and the digest-scope rule - This document - Member vocabulary
      defined in Section 5.6.1; digest algorithm is SHA-256 per
      [ACTA-RECEIPTS] with base64 encoding per [RFC4648].

   *  anchors - Scope: envelope-level - Envelope-level array of
      timestamp / transparency-log anchors covering the signed envelope;
      entries carry a REQUIRED type discriminator (rfc3161 or
      opentimestamps) and a REQUIRED value field, plus OPTIONAL
      informational members status (anchored / pending / failed) and
      bitcoin_block (string Bitcoin block hash for upgraded
      OpenTimestamps entries); full schema is defined in Section 5.4 -
      This document - Anchor type vocabulary: rfc3161 per [RFC3161],
      opentimestamps per [OPENTIMESTAMPS].

   This document additionally requests that IANA register
   counterparty_binding as a new claim in the CBOR Web Token (CWT)
   Claims registry established by [RFC8392], with this document as the
   reference and the semantics defined in Section 5.6.  The requested
   CWT claim key is TBD by IANA; this document proposes allocation from
   the IANA First Come First Served range (claim keys greater than or
   equal to -65536 and less than -256, or greater than or equal to
   65536, per [RFC8392] Section 9.1) so as not to consume Expert Review
   or Standards Action space.  The JSON-form claim name is the literal
   string counterparty_binding as registered above in the Compliance
   Receipt Extension Fields Registry.

11.2.  Compliance Receipt Type Namespaces Registry

   IANA is requested to create a new registry titled "Compliance Receipt
   Type Namespaces" under the same "Compliance Receipts" registry group.

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   Each entry contains:

   *  Namespace: a colon-separated identifier prefix used as a value of
      the type field, lowercase ASCII letters, digits, hyphen,
      underscore, and colon.

   *  Description: a one-line summary of the receipt category.

   *  Reference: the document that defines the namespace.

   The registration policy is Specification Required, per [RFC8126].
   The Designated Expert(s) SHOULD verify that the namespace does not
   collide with any namespace already registered or any namespace
   reserved by [ACTA-RECEIPTS], and that the Reference is a stable
   specification.

   Initial registry contents:

   *  protectmcp:acknowledgment - A receipt emitted by the B-party in a
      counterparty_binding pair, confirming receipt of the A-party
      action and carrying a digest of the bound envelope per Section 5.6
      - This document.

   *  protectmcp:decision - A receipt recording a policy evaluation
      outcome (allow, deny, rate_limit) for an MCP-mediated tool call
      where a policy was actually evaluated; observation is reserved to
      protectmcp:lifecycle per Section 5.2 - This document.

   *  protectmcp:restraint - A receipt recording the application or
      release of a restraint on an agent (e.g., quota, rate limit,
      sandbox tightening) - This document.

   *  protectmcp:lifecycle - A receipt recording an agent or system
      lifecycle event (e.g., configuration change, key rotation,
      oversight review, or a decision=observation record indicating an
      Action was signed without policy evaluation per Section 5.2) -
      This document.

   *  protectmcp:lifecycle:configuration_change - A receipt recording a
      configuration change to an agent or producing system, including
      changes that disable or re-enable receipt generation (see
      Section 6.1.1); a registered sub-namespace under
      protectmcp:lifecycle that the reference cloud implementation emits
      today - This document.

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12.  Acknowledgements

   The author thanks Tom Farley for [ACTA-RECEIPTS], on which this
   profile is built.  This profile would not exist without the field
   catalogue and envelope structure that the upstream draft defines.
   The author also thanks the Asqav community for review of early
   drafts.

13.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8032]  Josefsson, S. and I. Liusvaara, "Edwards-Curve Digital
              Signature Algorithm (EdDSA)", RFC 8032,
              DOI 10.17487/RFC8032, January 2017,
              <https://www.rfc-editor.org/info/rfc8032>.

   [RFC7518]  Jones, M., "JSON Web Algorithms (JWA)", RFC 7518,
              DOI 10.17487/RFC7518, May 2015,
              <https://www.rfc-editor.org/info/rfc7518>.

   [FIPS204]  National Institute of Standards and Technology, "Module-
              Lattice-Based Digital Signature Standard", FIPS 204,
              DOI 10.6028/NIST.FIPS.204, 13 August 2024,
              <https://csrc.nist.gov/pubs/fips/204/final>.

   [RFC5816]  Santesson, S. and N. Pope, "ESSCertIDv2 Update for RFC
              3161", RFC 5816, DOI 10.17487/RFC5816, April 2010,
              <https://www.rfc-editor.org/info/rfc5816>.

   [RFC3161]  Adams, C., Cain, P., Pinkas, D., and R. Zuccherato,
              "Internet X.509 Public Key Infrastructure Time-Stamp
              Protocol (TSP)", RFC 3161, DOI 10.17487/RFC3161, August
              2001, <https://www.rfc-editor.org/info/rfc3161>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

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   [OPENTIMESTAMPS]
              OpenTimestamps, "OpenTimestamps Server", September 2016,
              <https://github.com/opentimestamps/opentimestamps-server>.

   [ACTA-RECEIPTS]
              Farley, T., "Signed Decision Receipts for Machine-to-
              Machine Access Control", Work in Progress, Internet-Draft,
              draft-farley-acta-signed-receipts-01, 25 April 2026,
              <https://datatracker.ietf.org/doc/html/draft-farley-acta-
              signed-receipts-01>.

   [RFC8785]  Rundgren, A., Jordan, B., and S. Erdtman, "JSON
              Canonicalization Scheme (JCS)", RFC 8785,
              DOI 10.17487/RFC8785, June 2020,
              <https://www.rfc-editor.org/info/rfc8785>.

   [ISO17442] ISO, "Financial services - Legal entity identifier (LEI) -
              Part 1: Assignment", ISO 17442-1:2020, August 2020,
              <https://www.iso.org/standard/78829.html>.

   [W3C-DID]  W3C, "Decentralized Identifiers (DIDs) v1.0", 19 July
              2022, <https://www.w3.org/TR/did-1.0/>.

   [RFC9052]  Schaad, J., "CBOR Object Signing and Encryption (COSE):
              Structures and Process", STD 96, RFC 9052,
              DOI 10.17487/RFC9052, August 2022,
              <https://www.rfc-editor.org/info/rfc9052>.

   [RFC8949]  Bormann, C. and P. Hoffman, "Concise Binary Object
              Representation (CBOR)", STD 94, RFC 8949,
              DOI 10.17487/RFC8949, December 2020,
              <https://www.rfc-editor.org/info/rfc8949>.

   [RFC7515]  Jones, M., Bradley, J., and N. Sakimura, "JSON Web
              Signature (JWS)", RFC 7515, DOI 10.17487/RFC7515, May
              2015, <https://www.rfc-editor.org/info/rfc7515>.

   [RFC8392]  Jones, M., Wahlstroem, E., Erdtman, S., and H. Tschofenig,
              "CBOR Web Token (CWT)", RFC 8392, DOI 10.17487/RFC8392,
              May 2018, <https://www.rfc-editor.org/info/rfc8392>.

   [RFC4648]  Josefsson, S., "The Base16, Base32, and Base64 Data
              Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006,
              <https://www.rfc-editor.org/info/rfc4648>.

   [NIST-GENAI-PROFILE]
              National Institute of Standards and Technology,
              "Artificial Intelligence Risk Management Framework:

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              Generative Artificial Intelligence Profile", NIST AI
              600-1, DOI 10.6028/NIST.AI.600-1, 26 July 2024,
              <https://nvlpubs.nist.gov/nistpubs/ai/NIST.AI.600-1.pdf>.

14.  Informative References

   [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
              <https://www.rfc-editor.org/info/rfc8446>.

   [RFC5705]  Rescorla, E., "Keying Material Exporters for Transport
              Layer Security (TLS)", RFC 5705, DOI 10.17487/RFC5705,
              March 2010, <https://www.rfc-editor.org/info/rfc5705>.

   [RFC9266]  Whited, S., "Channel Bindings for TLS 1.3", RFC 9266,
              DOI 10.17487/RFC9266, July 2022,
              <https://www.rfc-editor.org/info/rfc9266>.

   [RFC9421]  Backman, A., Ed., Richer, J., Ed., and M. Sporny, "HTTP
              Message Signatures", RFC 9421, DOI 10.17487/RFC9421,
              February 2024, <https://www.rfc-editor.org/info/rfc9421>.

   [ISO8601-2]
              ISO, "Date and time - Representations for information
              interchange - Part 2: Extensions", ISO 8601-2:2019,
              February 2019, <https://www.iso.org/standard/70908.html>.

   [EU-AI-ACT]
              European Parliament and Council, "Regulation (EU)
              2024/1689 of the European Parliament and of the Council of
              13 June 2024 laying down harmonised rules on artificial
              intelligence and amending Regulations (EC) No 300/2008,
              (EU) No 167/2013, (EU) No 168/2013, (EU) 2018/858, (EU)
              2018/1139 and (EU) 2019/2144 and Directives 2014/90/EU,
              (EU) 2016/797 and (EU) 2020/1828 (Artificial Intelligence
              Act) (Text with EEA relevance)", 12 July 2024,
              <https://eur-lex.europa.eu/eli/reg/2024/1689/oj>.

   [DORA]     European Parliament and Council, "Regulation (EU)
              2022/2554 of the European Parliament and of the Council of
              14 December 2022 on digital operational resilience for the
              financial sector and amending Regulations (EC) No
              1060/2009, (EU) No 648/2012, (EU) No 600/2014, (EU) No
              909/2014 and (EU) 2016/1011 (Text with EEA relevance)", 27
              December 2022,
              <https://eur-lex.europa.eu/eli/reg/2022/2554/oj>.

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   [REG-2025-301]
              European Commission, "Commission Delegated Regulation (EU)
              2025/301 of 23 October 2024 supplementing Regulation (EU)
              2022/2554 of the European Parliament and of the Council
              with regard to regulatory technical standards specifying
              the content, timelines and templates on the reporting of
              major ICT-related incidents and significant cyber threats
              (Text with EEA relevance)", 20 February 2025,
              <https://eur-lex.europa.eu/eli/reg_del/2025/301/oj>.

   [REG-2025-302]
              European Commission, "Commission Implementing Regulation
              (EU) 2025/302 of 23 October 2024 laying down implementing
              technical standards for the application of Regulation (EU)
              2022/2554 of the European Parliament and of the Council
              with regard to the standard forms, templates, and
              procedures for financial entities to report a major ICT-
              related incident and to notify a significant cyber threat
              (Text with EEA relevance)", 20 February 2025,
              <https://eur-lex.europa.eu/eli/reg_impl/2025/302/oj>.

   [REG-2024-1772]
              European Commission, "Commission Delegated Regulation (EU)
              2024/1772 of 13 March 2024 supplementing Regulation (EU)
              2022/2554 of the European Parliament and of the Council
              with regard to regulatory technical standards specifying
              the criteria for the classification of ICT-related
              incidents and cyber threats, setting out materiality
              thresholds and specifying the details of reports of major
              incidents (Text with EEA relevance)", 25 June 2024,
              <https://eur-lex.europa.eu/eli/reg_del/2024/1772/oj>.

   [MIFID2]   European Parliament and Council, "Directive 2014/65/EU of
              the European Parliament and of the Council of 15 May 2014
              on markets in financial instruments and amending Directive
              2002/92/EC and Directive 2011/61/EU (recast) (Text with
              EEA relevance)", 12 June 2014,
              <https://eur-lex.europa.eu/eli/dir/2014/65/oj>.

   [REG-2017-565]
              European Commission, "Commission Delegated Regulation (EU)
              2017/565 of 25 April 2016 supplementing Directive 2014/65/
              EU of the European Parliament and of the Council as
              regards organisational requirements and operating
              conditions for investment firms and defined terms for the
              purposes of that Directive (Text with EEA relevance)", 31
              March 2017,
              <https://eur-lex.europa.eu/eli/reg_del/2017/565/oj>.

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   [AMLD]     European Parliament and Council, "Directive (EU) 2015/849
              of the European Parliament and of the Council of 20 May
              2015 on the prevention of the use of the financial system
              for the purposes of money laundering or terrorist
              financing, amending Regulation (EU) No 648/2012 of the
              European Parliament and of the Council, and repealing
              Directive 2005/60/EC of the European Parliament and of the
              Council and Commission Directive 2006/70/EC (Text with EEA
              relevance)", 5 June 2015,
              <https://eur-lex.europa.eu/eli/dir/2015/849/oj>.

   [AMLR]     European Parliament and Council, "Regulation (EU)
              2024/1624 of the European Parliament and of the Council of
              31 May 2024 on the prevention of the use of the financial
              system for the purposes of money laundering or terrorist
              financing (Text with EEA relevance)", 19 June 2024,
              <https://eur-lex.europa.eu/eli/reg/2024/1624/oj>.

   [NIST-AI-RMF]
              National Institute of Standards and Technology,
              "Artificial Intelligence Risk Management Framework (AI RMF
              1.0)", NIST AI 100-1, DOI 10.6028/NIST.AI.100-1, 26
              January 2023,
              <https://nvlpubs.nist.gov/nistpubs/ai/NIST.AI.100-1.pdf>.

   [COLORADO-AI-ACT]
              State of Colorado, Seventy-Fourth General Assembly,
              "Senate Bill 24-205, Consumer Protections for Artificial
              Intelligence", 17 May 2024,
              <https://leg.colorado.gov/bills/sb24-205>.

   [TEXAS-TRAIGA]
              State of Texas, 89th Legislature, Regular Session, "House
              Bill 149, Texas Responsible Artificial Intelligence
              Governance Act", 22 June 2025,
              <https://capitol.texas.gov/BillLookup/
              History.aspx?LegSess=89R&Bill=HB149>.

   [HIPAA-SECURITY]
              United States Department of Health and Human Services,
              "HIPAA Security Rule, 45 CFR Part 164, Subpart C, Security
              Standards for the Protection of Electronic Protected
              Health Information", 20 February 2003,
              <https://www.ecfr.gov/current/title-45/subtitle-A/
              subchapter-C/part-164>.

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   [NYDFS-500]
              New York State Department of Financial Services, "23 NYCRR
              Part 500, Cybersecurity Requirements for Financial
              Services Companies", 1 March 2017,
              <https://www.dfs.ny.gov/industry-guidance/cybersecurity>.

   [SEC-17A-4]
              United States Securities and Exchange Commission,
              "Electronic Recordkeeping Requirements for Broker-Dealers,
              Security-Based Swap Dealers, and Major Security-Based Swap
              Participants (Rule 17a-4 Amendments)", 3 November 2022,
              <https://www.federalregister.gov/
              documents/2022/11/03/2022-22670/electronic-recordkeeping-
              requirements-for-broker-dealers-security-based-swap-
              dealers-and-major>.  Effective date January 3, 2023;
              compliance date for amendments to 17 CFR 240.17a-4 May 3,
              2023.

   [CIRCIA]   United States Congress, "Cyber Incident Reporting for
              Critical Infrastructure Act of 2022, enacted as Division Y
              of the Consolidated Appropriations Act, 2022 (Public Law
              117-103); statutory authority codified at 6 U.S.C. 681 et
              seq.", 15 March 2022,
              <https://www.congress.gov/117/plaws/publ103/PLAW-
              117publ103.pdf>.  Public Law 117-103 was enacted on March
              15, 2022.  Implementing regulations are proceeding under a
              CISA notice of proposed rulemaking at 89 FR 23644 (April
              4, 2024); the final rule is pending publication.

Worked Example (Informative)

   This appendix illustrates a Compliance Receipt that satisfies the EU
   AI Act Article 26 binding for a tool invocation by a High-Risk AI
   System deployed by a Financial Entity.  The wire shape applies
   identically to United States bindings; the only differences are the
   values placed in issuer_id (LEI, EIN, or CIK depending on the regime)
   and in the risk_class and incident_class vocabularies referenced in
   the Audit Pack manifest.  Field values are abbreviated for
   readability and are not cryptographically valid.  The example shows a
   mid-chain receipt; a chain-genesis receipt would carry a
   previousReceiptHash of 64 zero hex characters per Section 5.3.

   The worked example below is illustrative.  The field values listed
   are real placeholders an implementer can canonicalize, but the keys
   are shown in human-readable order rather than JCS-canonical
   lexicographic order; the JCS-canonical bytes used as input to SHA-256
   reorder keys lexicographically (so the on-the-wire byte order for
   hashing is action_ref, decision, issued_at, issuer_id, iteration_id,

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   payload_digest, policy_digest, previousReceiptHash, reason,
   risk_class, sandbox_state, tool_name, type, with each nested object's
   keys also lexicographically sorted, per [RFC8785]).  The sig value,
   the anchors value entries, and the hash hex values are deterministic
   placeholders chosen for shape rather than cryptographic validity.
   Implementations MUST NOT replay or trust this example as a real
   receipt; the example is not signed by any allocated issuer_id, is not
   anchored against any TSA or OpenTimestamps calendar, and does not
   chain into any retained predecessor.

   {
     "payload": {
       "type": "protectmcp:decision",
       "issued_at": "2026-05-04T09:14:22.118Z",
       "issuer_id": "00000000000000000098",
       "action_ref": "c1f3a09a4d2e7f6b8c5a91e3d7b04f2a1c8e6f5d3b9a7c2e4f8d6b1a3c5e7f9d",
       "tool_name": "deploy",
       "iteration_id": "task-2026-05-04-01a3",
       "decision": "allow",
       "reason": "policy:within_limits",
       "policy_digest": "sha256:7b214e8c3d9f4a2b1e6c8f5a3d7b9e2c4f6a8d1b3e5c7f9a2d4b6e8c1f3a5d7b",
       "sandbox_state": "enabled",
       "payload_digest": {
         "hash": "0a44d2c8e3f5b7a9d1c4e6f8b2a5d7c9e1f3b5a7d9c2e4f6b8a1d3c5e7f9b2a4",
         "size": 1024
       },
       "previousReceiptHash": "f80c11a3b5d7e9c2f4a6b8d1e3c5f7a9b2d4e6c8f1a3b5d7e9c2f4a6b8d1e3c5",
       "risk_class": "deployer:financial:medium"
     },
     "signature": {
       "alg": "EdDSA",
       "kid": "00000000000000000098",
       "sig": "..."
     },
     "anchors": [
       {
         "type": "rfc3161",
         "value": "..."
       },
       {
         "type": "opentimestamps",
         "value": "..."
       }
     ]
   }

   The above receipt satisfies the Article 26 binding because:

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   *  issuer_id is a 20-character ISO 17442 Legal Entity Identifier
      (LEI) that resolves through the trust anchor metadata in the Audit
      Pack to the named Deployer;

   *  policy_digest resolves to a retained policy artefact;

   *  sandbox_state is enabled, satisfying the High-Risk system
      constraint of Section 5.1.6;

   *  previousReceiptHash links the receipt into the chain per
      Section 5.3;

   *  both an [RFC3161] anchor and an [OPENTIMESTAMPS] anchor are
      present per Section 5.4.

   Under the DORA Article 17 binding a Compliance Verifier additionally
   checks the longest applicable sectoral retention floor (1827 days as
   the default, per Section 6.3.4) and, where present, that
   incident_class flattens to the canonical six-value vocabulary
   referenced in Section 5.5.  Under the United States bindings of
   Section 6 the same verifier additionally checks the longest
   applicable retention floor (2192 days as the default for receipts
   under Section 7.4 or Section 7.6) and, where the Deployer is a NYDFS
   Covered Entity, a HIPAA Covered Entity, or a CIRCIA Covered Entity,
   that incident_class resolves to the applicable canonical category for
   each in-scope regime.

Change Log

draft-marques-asqav-compliance-receipts-04

   Cross-agent integrity revision.  The threat case is a compromised
   intermediary that swaps payload bytes between two honest agents while
   both per-agent hash chains validate independently.

   *  Section 5.3 digest-scope correction.  The chain-link digest scope
      is the canonical signing-input bytes (the JCS-canonical
      serialization of the predecessor's signed payload object, the same
      bytes the predecessor's signature covers), NOT the envelope object
      that additionally includes the signature or anchors top-level
      keys.  The earlier -04 text that said the digest covers "the
      entire signed receipt object including the signature field" was a
      Security Considerations over-reach that did not match the
      reference implementation and would have required every deployed
      chain to be re-issued.  The corrected scope matches both the
      reference implementation and the upstream [ACTA-RECEIPTS]
      Section 5.7 rule.  The security rationale is updated accordingly:
      the chain binds the signed-over content of the predecessor

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      (recomputable offline from the predecessor's payload alone), and
      cross-agent envelope-including-signature integrity is delegated to
      counterparty_binding (Section 5.6), which IS at the envelope-
      including-signature scope precisely because the peer signature is
      the load-bearing artefact in that case.  Section 9.1 is updated to
      match.

   *  New informative Section 10.2 in Security Considerations
      acknowledges that the single-linear per-agent chain rule of
      Section 5.3 creates a per-issuer serialization bottleneck: a
      denial-of-service against the predecessor pointer (database lock,
      network partition, slow IO) bounds chain throughput.  Mitigation:
      issuers SHOULD use bounded predecessor-lookup timeouts, emit a
      structured protectmcp:lifecycle audit event with a stable
      chain_emission_blocked reason code when the timeout fires, and
      document a chain-head recovery procedure for crashed emitters.
      Parallel per-issuer throughput beyond a single linear chain
      remains the existing distinct-issuer_id escape hatch.

   *  Section 10.12 residual list is rewritten for honesty.  The M+B
      collusion residual is downgraded from "M+B alone defeats
      counterparty_binding" to "M+B+(A's-storage compromise or
      unavailability) defeats counterparty_binding": the audit-time
      verifier resolves receipt_ref to A's retained envelope and
      recomputes the digest, so an honest reachable A's storage defeats
      M+B collusion alone.  A new M+A collusion residual is added: M and
      A coordinating to produce a fraudulent A-signed envelope is
      fundamentally outside the receipt model's threat surface because
      every cryptographic invariant holds; mitigation is separation of
      duties between issuer and intermediary plus anchor evidence on
      independent witnesses under different trust roots.

   *  The worked-example appendix carries an explicit disclaimer that
      the keys are shown in human-readable order (not JCS-canonical
      lexicographic order), the sig/value/hash bytes are deterministic
      placeholders, and implementations MUST NOT replay or trust the
      example as a real receipt.  The disclaimer states the JCS-
      canonical key ordering that an implementer would derive on the
      wire.

   *  Section 5.6.1 envelope_hash rule is tightened on three axes.
      First, the base64 alphabet is no longer ambiguous: standard base64
      per [RFC4648] Section 4 on emission, OR base64url per Section 5
      where the transport requires URL-safe encoding, and verifiers MUST
      accept both and normalise before comparison.  Second, JSON-framed
      digest scope is now normative and mandatory-to-implement: the JCS-
      canonical UTF-8 byte sequence of A's signed envelope JSON object
      per [RFC8785], where the envelope is the three-key object

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      {"payload", "signature", "anchors"} with anchors OPTIONAL and B
      forbidden from re-canonicalizing or stripping any of the three
      keys before computing the digest.  Third, cross-framing
      equivalence is explicitly addressed: JCS-canonical JSON, COSE
      deterministic encoding, and JWS Compact Serialization with JCS-
      canonical payload produce different byte sequences from the same
      semantic payload-and-signature, so envelope_hash is framing-
      specific; a transcoding intermediary that re-frames A's envelope
      MUST be treated as a tampering event, and verifiers MUST NOT
      reframe before recomputing.

   *  Section 11.1 entries now carry an explicit Scope tag (signed-
      payload for risk_class, incident_class, counterparty_binding;
      envelope-level for anchors).  The CWT claim request for
      counterparty_binding now proposes allocation from the IANA First
      Come First Served range of [RFC8392] Section 9.1 rather than the
      unqualified "unassigned integer range" placeholder, so as not to
      consume Expert Review or Standards Action space.

   *  The [CIRCIA] reference is corrected to cite the statutory
      authority (Public Law 117-103 Division Y, codified at 6 U.S.C. 681
      et seq.) rather than CISA's general topic page; the March 15, 2022
      enactment date is retained, and the pending NPRM at 89 FR 23644
      (April 4, 2024) is named in the reference annotation.

   *  New normative Section 4.6 (Section 5.6) defines the
      counterparty_binding extension field, an in-payload object
      carrying a base64-encoded SHA-256 digest (envelope_hash) over the
      full signed envelope of a peer agent (including the peer's
      signature bytes), a resolvable opaque receipt_ref, an OPTIONAL
      expect_ack_from identifier (kid/issuer_id of the expected
      acknowledger), and an OPTIONAL operational transport_label.
      Section 4.6.3 (Section 5.6.3) defines the MUST-reject rule when
      the bound digest does not resolve, the storage obligation on the
      Audit Pack production layer, and the pairwise default for N-
      greater-than-2 chains.

   *  The anchors top-level array schema is now defined inline in
      Section 5.4: each entry MUST carry type and value (base64-encoded
      anchor token bytes), with OPTIONAL informational status (anchored
      / pending / failed) and bitcoin_block (Bitcoin block hash for
      upgraded OpenTimestamps entries).  The IANA Extension Fields
      Registry entry for anchors is updated to reflect the four-member
      schema.

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   *  The IANA Type Namespaces Registry initial contents now include the
      registered sub-namespace protectmcp:lifecycle:configuration_change
      emitted by the reference cloud implementation for configuration-
      change receipts under Section 6.1.1.

   *  CIRCIA retention floor (Section 7.7.2) is rewritten to measure two
      years from the submission of the most recently required CIRCIA
      report per proposed Section 226.13(c) of the CIRCIA NPRM at 89 FR
      23644 (April 4, 2024), not from the date of the underlying Action.

   *  HIPAA retention (Section 7.4.2) is rewritten to cite 45 CFR
      164.316(b)(2) with the six-year floor expressed as "six years from
      the date of creation or the date when last in effect, whichever is
      later" and the analogy basis for applying that floor to audit-log
      content explicitly named.

   *  EU AI Act Article 26(6) retention (Section 6.1.5) is rewritten to
      express the six-month floor in calendar-arithmetic terms per
      [ISO8601-2]; the 184-day day-count figure is retained as an
      informative anchoring-interval floor, and the previously-endorsed
      183-day pick is withdrawn.

   *  Section 5.1.3 now states explicitly that issuer_id values MUST be
      bare identifiers without a scheme prefix where the scheme is
      unambiguous (LEI: 20-character alphanumeric self-identifying
      form), aligning the spec with the reference cloud emitter under
      the cloud-wire-conformance change.

   *  New informative Section 9.11 (Section 10.12) documents the
      residual threat that counterparty_binding partially mitigates (M
      silently swaps bytes between honest A and B) and names three
      operational mitigations Operators SHOULD adopt: multiple
      independent anchor witnesses, regulator-driven side-by-side chain
      comparison under SEC 17a-4 audit-trail workflow, and out-of-band M
      relay logs.

   *  Section 7 (Section 8) records two manifest-level fields shipped in
      the reference Audit Pack producer: regime_mapping_disclaimer (when
      per-receipt regime predicates derive from a producer-side mapping
      the original signer did not co-sign) and stale_pending (per-entry
      flag set when anchor evidence remains pending after the bound of
      Section 5.4).

   *  Section 8.3 (Section 9.3) replaces the prior one-paragraph clause
      with five SHOULD-emit per-axis fields: regimes_satisfied,
      anchor_valid_ots, anchor_valid_rfc3161, policy_digest_resolved,
      duplicate_emission_candidate.

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   *  New informative Section 9.9 (Section 10.10) enumerates the
      residuals counterparty_binding does not solve.  New informative
      Section 9.10 (Section 10.11) records channel-level operator
      guidance citing [RFC8446], [RFC9266], [RFC5705], and [RFC9421] and
      disclaims transport-layer security as a substitute for
      application-layer byte equality.

   *  Section 11 (Section 11) adds counterparty_binding to the Extension
      Fields Registry and requests registration as a CWT claim per
      [RFC8392].

   *  New normative references: [RFC9052], [RFC8949], [RFC7515],
      [RFC8392].  New informative references for channel-level guidance
      only: [RFC8446], [RFC5705], [RFC9266], [RFC9421].

   *  New normative Section 4 bounds the inputs to which the inherited
      JCS rule of [RFC8785] is applied: IEEE-754 floating-point numbers
      MUST NOT appear in the digest-covered canonical form (callers
      SHOULD serialize numerics as JSON strings or as integer-rational
      pairs in the IEEE-754 safe range), and tool-version-specific
      semantic equivalence (SQL case folding, path normalization,
      locale-aware string collation, numeric tolerance, URL percent-
      encoding choices) is OUT OF SCOPE for the chain layer.  The chain
      answers byte equality for one agent identity at one wall-clock
      time only; semantic equivalence belongs in the policy_digest
      artefact and the Audit Pack manifest.

   *  Section 5.3 now states explicitly that each issuer MUST maintain a
      single linear per-agent chain and MUST serialize concurrent in-
      agent emission (parallel tool calls, thread-pool fan-out) through
      a single predecessor pointer in emission order.  Parallel sub-
      chains within one agent identity (a per-receipt chain_id
      discriminator) are NOT defined by this profile; an issuer that
      requires parallel sub-chains MUST express each parallel path as a
      distinct agent identity with its own issuer_id, signing key, and
      chain rooted at the all-zero genesis value.

   *  Wire tightenings introduced in this revision (additive at the
      message level, restrictive at the verifier level): (a) the anchors
      entry value member is now REQUIRED where the upstream profile
      leaves it OPTIONAL; (b) issuer chains are normatively single-
      linear per issuer (no parallel chain_id discriminator), so a -03
      producer that ran parallel sub-chains under one issuer_id emits
      non-conformant -04 receipts; and (c) IEEE-754 floating-point
      numbers MUST NOT appear in the canonical form covered by SHA-256
      digests.  A -03 receipt with a missing anchor value, parallel sub-
      chains, or a digest-covered float is not a conformant -04 receipt.
      Implementations targeting -04 SHOULD re-emit -03 receipts under

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      -04 emission rules.  The signing algorithms, the canonicalization
      transformation itself (JCS), the anchor types, and the regime
      bindings of Sections 5 and 6 are unchanged.  A -03 verifier
      remains conformant for receipts that do not carry
      counterparty_binding; -03 verifiers encountering the field will
      ignore it per [ACTA-RECEIPTS] Section 4.2 extension semantics.

   *  Rationale paragraph of Section 4 is rewritten to ground the
      IEEE-754 float ban on documented divergence between mainstream
      JSON serializers (Python json.dumps, Go encoding/json, Java
      Jackson) and the ECMA-262 Number-to-String algorithm referenced by
      Section 3.2.2.3 of [RFC8785], rather than on a misstated claim
      that JCS itself fails to specify float serialization outside the
      safe integer range.  The Unicode-normalization bullet of Section 4
      is corrected to acknowledge that Section 3.1 of [RFC8785] mandates
      as-is preservation of Unicode strings (no NFC default).

   *  Security Considerations Section 10.1 is corrected to reflect the
      tiered DORA deadlines: the four-hour initial-notice clock (with
      72-hour intermediate-report and one-month final-report bounds) per
      DORA Article 17 and the RTS in [REG-2025-301], rather than a flat
      72-hour reporting deadline.  New informative reference
      [REG-2025-301] added.

   *  The Annex II field 3.23 (Type of the incident) citation in
      Section 5.5 and the incident_class initial-registry entry of
      Section 11.1 no longer reproduces the enumeration verbatim;
      verifiers MUST resolve the canonical values from [REG-2025-302]
      directly.

   *  Section 5.2 extends the wire decision vocabulary with observation,
      a fourth value reserved to type protectmcp:lifecycle for receipts
      emitted when an Action was signed without any policy evaluation.
      The new value is the regulator-honest alternative to a misleading
      allow on the "no policy matched" path; emitters MUST refuse to
      issue a protectmcp:decision receipt that carries observation, and
      verifiers MUST reject the combination.  The vocabulary-namespace
      registry entry for protectmcp:decision in Section 11.2 is updated
      to reflect that observation is reserved to protectmcp:lifecycle.

   *  New informative appendix (Appendix "Appendix - Capture Topologies
      for Compliance Receipt Emission") catalogues five capture
      topologies an operator can use to emit conformant Compliance
      Receipts in environments where the originating application code
      cannot be modified to call the receipt-emitting SDK directly:
      in_process_sdk, network_proxy, browser_extension, ebpf_observer,
      mcp_proxy.  The appendix is non-normative; the capture_topology
      attribute it defines is OPTIONAL at the wire layer and, where

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      present, lives in the Audit Pack manifest entry rather than inside
      the signed payload object, so the topology declaration does not
      alter signed bytes.  The five values form a closed initial
      vocabulary at this revision; Appendix "capture_topology Vocabulary
      and Considerations for a Future IANA Registry" sketches a future
      "Compliance Receipt Capture Topologies" IANA registry under the
      "Compliance Receipts" registry group with Specification Required
      registration policy per [RFC8126] for a follow-on revision, and
      names reserved-value avoidance guidance for early extenders.

draft-marques-asqav-compliance-receipts-03

   Multi-jurisdiction consolidation.  The European Union profile
   (formerly the only profile in -02) and the United States profile
   (formerly the separate draft draft-marques-asqav-us-compliance-
   receipts-00) are merged into a single document with two regional
   bindings sections: Section 5 (European Union) and Section 6 (United
   States).  Sections 1 through 4 (Introduction, Conventions,
   Relationship to upstream, Receipt Field Profile) and Sections 7
   through 11 (Audit Pack, Verifier, Security, IANA, Acknowledgements)
   are shared across both regimes.  Conventions terms that differ across
   regimes are now disambiguated with regime suffixes (Deployer (EU AI
   Act) vs Deployer (Colorado AI Act); High-Risk AI System (EU AI Act)
   vs High-Risk AI System (Colorado AI Act)).  The incident_class
   extension field now lists every applicable canonical category in one
   place: ICT-related incident under [DORA] with the Annex II reporting
   enumeration, Cybersecurity Event/Incident under [NYDFS-500], Covered
   Cyber Incident under [CIRCIA], and security incident under
   [HIPAA-SECURITY].  The issuer_id rule now permits EIN or CIK as
   alternatives to LEI for US Deployers without an allocated LEI.  The
   Tamper Resistance security consideration extends the one-hour
   anchoring SHOULD to NYDFS 500.17 and CIRCIA in addition to DORA
   Article 17.  The Privacy security consideration extends to GDPR for
   EU data subjects and CCPA / VCDPA / HIPAA Privacy Rule for US data
   subjects.  The Worked Example notes that the wire shape applies
   identically to US bindings, with only the issuer_id identifier and
   the vocabularies differing.  IANA registries are unchanged; the
   Initial registry contents for incident_class now describe the multi-
   regime category set.  No changes to the wire format, the field
   profile, the hash chain, the anchoring rules, the Audit Pack
   contents, or the Verifier checks.  Section 4.1.6 (sandbox_state) and
   Section 4.5 (risk_class) corrected to attribute the EU risk-
   management documentation requirement to Article 9 of [EU-AI-ACT]
   (Provider's risk management system) rather than Article 26, with
   Article 26(1) cited as the deployer's instructions-for-use obligation
   that links to the Provider's Article 9 documentation.  Section 6.5.3
   (nydfs-retention) corrected to a single-tier five-year floor under 23
   NYCRR 500.6(b) (verified verbatim against LII Cornell); the prior

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   tiered 5-year/3-year split (claimed against the DFS Second Amendment)
   was incorrect because the Second Amendment does not amend
   Section 500.6, leaving the 2017 single-tier text in force.  The
   1096-day three-year audit-trail floor previously stated for NYDFS is
   removed.

draft-marques-asqav-compliance-receipts-02

   Submission-ready EU-only profile.  Wire-shape alignment with upstream
   [ACTA-RECEIPTS] (payload/signature/anchors envelope; payload_digest
   object form; tool_name REQUIRED for protectmcp:decision; issuer_id
   equals kid).  EU AI Act and DORA bindings authored against Official
   Journal text.  Anchor MUST (at least one of RFC 3161 or
   OpenTimestamps); both RECOMMENDED; 7-day OpenTimestamps upgrade
   deadline profile-imposed.  Six-month AI Act floor expressed as 184
   days; DORA-bound default expressed as 1827 days.  IANA registries
   created.

draft-marques-asqav-compliance-receipts-01

   Initial wire-shape alignment with upstream and addition of dual-
   anchor, hash-chain, retention, and DORA classification bindings.
   Subsequent revisions superseded the specific values introduced here.

draft-marques-asqav-compliance-receipts-00

   Initial version.  Defines a profile of [ACTA-RECEIPTS] that binds
   receipt fields to EU AI Act Article 12, EU AI Act Article 26, and
   DORA Article 17.

Appendix - Capture Topologies for Compliance Receipt Emission

   This appendix is informational and non-normative.  It catalogues five
   capture topologies an operator can use to emit conformant Compliance
   Receipts in environments where the originating application code
   cannot be modified to call the receipt-emitting SDK directly.  The
   topologies are listed in order of payload fidelity, from highest (in-
   process SDK, full payload digest) to lowest (eBPF observer,
   connection metadata only).  All five emit receipts that satisfy the
   wire profile of Sections 3 and 4; they differ in trust boundary,
   payload coverage, and the operational identity that the receipt
   binds.  The intent is to give an operator vocabulary for declaring
   which topology produced a given receipt, so that a verifier or
   auditor can interpret the receipt's evidentiary weight without re-
   deriving the architecture from out-of-band documentation.

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   An operator MAY declare the producing topology by including a
   capture_topology attribute in the Audit Pack manifest entry for the
   receipt.  The attribute is informational at the wire layer and
   OPTIONAL.  The vocabulary defined below is closed for the topologies
   catalogued in this appendix; future revisions or third-party profiles
   MAY extend it through the future-IANA-registry mechanism noted at the
   end of this appendix.

In-Process SDK

   The originating application links the receipt-emitting SDK directly
   and calls it inline with the action being recorded.  This is the
   baseline pattern [ACTA-RECEIPTS] and Sections 3 and 4 of this
   document are written against.  The receipt carries a full
   payload_digest covering the action's request bytes; the SDK has
   direct access to the application's principal identity, the policy
   decision, and the request body.  Vocabulary value: in_process_sdk.
   Trust boundary: the application process itself; the SDK runs inside
   the application's memory space and inherits its principal.  Threat-
   model note: captures the full request and response payloads, the
   deciding principal, and the policy context; does NOT capture out-of-
   process side effects or actions taken by sibling processes that do
   not link the SDK.  Reference implementation hint: the Asqav Python
   and TypeScript SDKs published under the asqav-sdk umbrella (Apache-
   2.0) implement this pattern; an operator MAY substitute any other
   conformant [ACTA-RECEIPTS] implementation.

Network-Layer Egress Proxy

   A customer-owned reverse proxy or egress gateway (Envoy, NGINX, or an
   equivalent forward proxy) sits in the network path between the
   application and the downstream LLM provider.  The proxy tees the
   request to a co-located Compliance Signer process, which receives the
   request bytes, applies the policy evaluation, and emits a receipt via
   a signer RPC.  A DNS-rewrite on-ramp (CoreDNS rewriting the LLM
   hostname to the proxy address) or a Server Name Indication (SNI)
   router (SNIProxy at Layer 4) MAY be used to force application traffic
   onto the proxy without per-application configuration.  Vocabulary
   value: network_proxy.  Trust boundary: the customer's network egress;
   the proxy and signer run under the customer's operational control,
   and the receipt is signed by a key the customer's signer holds.
   Threat-model note: captures the request and response bytes that
   traverse the proxy and the network-layer principal identity (source
   IP, mTLS client cert if present); does NOT capture traffic that
   bypasses the proxy (direct outbound from a non-routed host, DNS-over-
   HTTPS to a hard-coded resolver, or TLS connections to certificate-
   pinned endpoints that the customer's enterprise CA cannot inspect).
   The receipt's issuer_id binds the customer's signer, not the

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   originating application; the application's identity, where captured,
   appears as an attribute resolved through the Audit Pack manifest.
   Reference implementation hint: CoreDNS (Apache-2.0) for the DNS on-
   ramp, SNIProxy by dlundquist (BSD-2-Clause) for the SNI router, and
   Envoy (Apache-2.0) for the Layer-7 reverse proxy plane; none of these
   are normative requirements.

Browser Extension

   A managed-browser Manifest V3 (MV3) extension installed on employee
   workstations via the enterprise MDM intercepts fetch, XMLHttpRequest,
   and EventSource requests to a configured list of LLM hostnames.  The
   extension POSTs the intercepted request and response bytes to a
   Compliance Signer endpoint, which emits the receipt.  For LLM hosts
   that pin their TLS certificates, the customer's enterprise root
   Certificate Authority (CA) MUST be installed in the browser trust
   store via MDM so that the extension's content-script interception can
   observe decrypted bytes.  Vocabulary value: browser_extension.  Trust
   boundary: the managed browser process on the employee workstation;
   the extension runs under the browser's sandbox and the employee's
   interactive session.  Threat-model note: captures the full request
   and response payload for LLM calls initiated from the browser by the
   human user, and binds the receipt to the browser's principal identity
   (the user's enterprise single-sign-on subject, where the extension
   can read it).  Does NOT capture LLM calls made by native desktop
   applications, server-side daemons, or browsers without the extension
   installed; does NOT capture traffic in incognito or private-window
   modes unless the extension is explicitly authorised for those
   contexts.  Reference implementation hint: the open-source Chrome MV3
   extension scaffolding published by Google under the chrome-
   extensions-samples repository (Apache-2.0) is a useful starting
   point; the customer's signer endpoint is the Asqav signer or any
   conformant [ACTA-RECEIPTS] implementation.

eBPF SNI Observer

   A kernel-level extended Berkeley Packet Filter (eBPF) probe attached
   to the host's network stack observes outbound TLS ClientHello
   records.  The probe extracts the SNI hostname, the JA3 client
   fingerprint, the source and destination addresses and ports, and the
   connection timestamp, and emits a lower-fidelity receipt that binds
   the employee, the device, the wall-clock time, and the LLM host
   without observing payload content.  Vocabulary value: ebpf_observer.
   The receipt SHOULD carry an informational payload_capture attribute
   set to false in the Audit Pack manifest, so that a verifier or
   auditor does not assume payload-level evidence is recoverable.  Trust
   boundary: the kernel of the host on which the probe runs; the probe
   operates below the application's user-space process and observes

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   traffic regardless of application configuration.  Threat-model note:
   captures the existence and counterparty of an LLM call (the "did the
   call happen" evidence class) and the device-and-employee binding
   through host attestation; does NOT capture request or response bytes,
   the prompt content, the model parameters, or the decision-relevant
   context.  Useful when payload capture is operationally infeasible
   (TLS certificate pinning that the enterprise CA cannot defeat, third-
   party SaaS that egresses outside the customer's proxy plane) but the
   operator still needs evidence that a regulated LLM interaction
   occurred.  Reference implementation hint: Inspektor Gadget (Apache-
   2.0) and Tetragon (Apache-2.0) both expose SNI and connection-
   metadata events from eBPF probes; neither is a normative requirement.

MCP Transparent Proxy

   A transparent proxy sits in-path between a Model Context Protocol
   (MCP) client and one or more downstream MCP servers, terminating the
   client's stdio, Server-Sent Events (SSE), or streamable-HTTP
   transport on one side and re-establishing the same transport to each
   downstream server on the other side.  The proxy observes every tools/
   call and resources/read JSON-RPC method invocation, signs a receipt
   at the moment the call is forwarded, and emits a second acknowledging
   receipt carrying a counterparty_binding (see Section 5.6) at the
   moment the downstream server's response returns.  Both sides of the
   call are therefore bound bilaterally, with the proxy's signing key
   serving as the integrity anchor for the pair.  Vocabulary value:
   mcp_proxy.  The receipt SHOULD carry the invoked MCP method (for
   example, tools/call or resources/read) as an attribute in the Audit
   Pack manifest entry, so that a verifier can filter by call type
   without re-parsing payload bytes.  Trust boundary: the proxy process
   and its signing key; the upstream MCP client and the downstream MCP
   server are both treated as honest endpoints under the threat model of
   Section 10.12, with the proxy itself being the named intermediary
   whose tampering risk counterparty_binding mitigates.  Threat-model
   note: captures the full MCP request and response payload, the method
   name, and the client and server principal identities visible at the
   transport boundary; does NOT capture MCP traffic that bypasses the
   proxy or that uses a transport the proxy does not implement.
   Reference implementation hint: the Asqav MCP transparent proxy
   published under the asqav-mcp repository (Apache-2.0) and the
   upstream FastMCP project (MIT) on which it builds; neither is a
   normative requirement.

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capture_topology Vocabulary and Considerations for a Future IANA
Registry

   The five values defined in this appendix (in_process_sdk,
   network_proxy, browser_extension, ebpf_observer, mcp_proxy) form the
   closed initial vocabulary for the capture_topology attribute.  The
   attribute is OPTIONAL at the wire layer and, where present, MUST
   appear in the Audit Pack manifest entry for the receipt rather than
   inside the signed payload object, so that the topology declaration is
   producer-side metadata that does not alter the receipt's signed
   bytes.  A verifier MUST NOT treat the absence of a capture_topology
   attribute as a non-conformance condition; absence simply means the
   producer did not declare a topology.

   This document is an Independent Submission and does not request IANA
   action for the capture_topology vocabulary at this revision.  A
   future revision MAY request creation of a "Compliance Receipt Capture
   Topologies" registry under the same "Compliance Receipts" registry
   group described in Section 11, with the registration policy of
   Specification Required per [RFC8126] and an initial set populated
   from the five values above.  Until such a registry exists,
   implementations that extend the vocabulary SHOULD document the new
   value in a reference specification and SHOULD avoid colliding with
   the five reserved values above.  The Designated Expert(s) for any
   future registry SHOULD verify that a candidate value names a distinct
   topology (a different trust boundary or a materially different
   payload-fidelity class) rather than a variant of an existing one, and
   that the candidate's threat-model note states what is captured and
   what is not, in the form used by the five entries in this appendix.

Author's Address

   Joao Andre Gomes Marques
   Asqav
   Portugal
   Email: joaoagm90@gmail.com

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