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RVP: Real-time Verification Protocol - Continuous Identity and Process Verification
draft-vandemeent-rvp-continuous-verification-01

Document Type Active Internet-Draft (individual)
Authors Jasper van de Meent , Root AI
Last updated 2026-03-29
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Reference implementation: tibet-triage Python package
tibet-core on PyPI
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draft-vandemeent-rvp-continuous-verification-01
Internet Engineering Task Force                          J. van de Meent
Internet-Draft                                                     R. AI
Intended status: Informational                                  Humotica
Expires: 30 September 2026                                 29 March 2026

 RVP: Real-time Verification Protocol - Continuous Identity and Process
                              Verification
            draft-vandemeent-rvp-continuous-verification-01

Abstract

   This document defines RVP (Real-time Verification Protocol), a
   protocol for continuous identity verification through ordered
   cascades of verification methods.  Unlike traditional authentication
   models that verify once and trust until session expiry, RVP treats
   every interaction as a verification moment.  Each moment produces a
   Verification Token: a cryptographic evidence record capturing which
   methods were used, what confidence each produced, and whether the
   accumulated confidence meets the required threshold.

   RVP defines a Verification Cascade: an ordered chain of verification
   methods (behavioral biometrics, physical identity, device context)
   where each layer activates only when preceding layers produce
   insufficient confidence.  The cascade produces evidence at every
   step; enforcement is a local policy decision.

   RVP integrates with TIBET [TIBET] for provenance tokens and JIS [JIS]
   for identity semantics.  The protocol is designed for local-first
   operation with no dependency on centralized identity providers.

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/.

   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 30 September 2026.

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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.  Code Components
   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Problem Statement . . . . . . . . . . . . . . . . . . . .   3
     1.2.  Design Principles . . . . . . . . . . . . . . . . . . . .   4
     1.3.  Scope . . . . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   5
   3.  Protocol Overview . . . . . . . . . . . . . . . . . . . . . .   6
     3.1.  Continuous vs. Session-Based Verification . . . . . . . .   6
     3.2.  The Verification Moment . . . . . . . . . . . . . . . . .   6
   4.  Verification Cascade  . . . . . . . . . . . . . . . . . . . .   6
     4.1.  Cascade Layers  . . . . . . . . . . . . . . . . . . . . .   6
     4.2.  Layer Activation  . . . . . . . . . . . . . . . . . . . .   7
     4.3.  Confidence Scoring  . . . . . . . . . . . . . . . . . . .   7
     4.4.  Cascade Resolution  . . . . . . . . . . . . . . . . . . .   8
   5.  Telemetry Layers  . . . . . . . . . . . . . . . . . . . . . .   8
     5.1.  L1 KEYSTROKE - Behavioral Biometrics  . . . . . . . . . .   8
     5.2.  L2 BIOMETRIC - Physical Identity  . . . . . . . . . . . .   8
     5.3.  L3 DEVICE - Hardware and Network Context  . . . . . . . .   9
     5.4.  L4 VOCAL - Acoustic Telemetry . . . . . . . . . . . . . .   9
     5.5.  L5 BEHAVIORAL - Intent Analysis . . . . . . . . . . . . .   9
   6.  Verification Token  . . . . . . . . . . . . . . . . . . . . .   9
     6.1.  Token Structure . . . . . . . . . . . . . . . . . . . . .   9
     6.2.  Token Chain . . . . . . . . . . . . . . . . . . . . . . .  10
     6.3.  TIBET Integration . . . . . . . . . . . . . . . . . . . .  11
   7.  Cascade Fallback Protocol . . . . . . . . . . . . . . . . . .  11
     7.1.  Fallback Triggers . . . . . . . . . . . . . . . . . . . .  11
     7.2.  Hard Stop Conditions  . . . . . . . . . . . . . . . . . .  11
   8.  Credential Binding  . . . . . . . . . . . . . . . . . . . . .  12
     8.1.  W3C Verifiable Credentials Integration  . . . . . . . . .  12
     8.2.  Credential Presentation with RVP Proof  . . . . . . . . .  12
   9.  Local-First Architecture  . . . . . . . . . . . . . . . . . .  12
     9.1.  On-Device Processing  . . . . . . . . . . . . . . . . . .  12
     9.2.  Network Independence  . . . . . . . . . . . . . . . . . .  13

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   10. Transport Considerations  . . . . . . . . . . . . . . . . . .  13
   11. Privacy Considerations  . . . . . . . . . . . . . . . . . . .  13
     11.1.  Biometric Data Protection  . . . . . . . . . . . . . . .  13
     11.2.  Telemetry Minimization . . . . . . . . . . . . . . . . .  13
     11.3.  Selective Disclosure . . . . . . . . . . . . . . . . . .  14
   12. Security Considerations . . . . . . . . . . . . . . . . . . .  14
     12.1.  Evidence vs. Enforcement . . . . . . . . . . . . . . . .  14
     12.2.  Replay Attacks . . . . . . . . . . . . . . . . . . . . .  14
     12.3.  Adversarial Inputs . . . . . . . . . . . . . . . . . . .  14
     12.4.  Cascade Limitations  . . . . . . . . . . . . . . . . . .  14
   13. Regulatory Considerations . . . . . . . . . . . . . . . . . .  15
   14. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  15
   15. References  . . . . . . . . . . . . . . . . . . . . . . . . .  15
     15.1.  Normative References . . . . . . . . . . . . . . . . . .  15
     15.2.  Informative References . . . . . . . . . . . . . . . . .  16
   Appendix A.  Verification Token JSON Schema . . . . . . . . . . .  17
   Appendix B.  Cascade Configuration Schema . . . . . . . . . . . .  17
   Appendix C.  Use Case Examples  . . . . . . . . . . . . . . . . .  17
     C.1.  Age Verification at Point of Sale . . . . . . . . . . . .  17
     C.2.  Continuous Developer Authentication . . . . . . . . . . .  17
     C.3.  Child on Parent's Device  . . . . . . . . . . . . . . . .  17
   Appendix D.  Predictive Airlock (Future Extension)  . . . . . . .  17
   Appendix E.  Changes from -00 . . . . . . . . . . . . . . . . . .  18
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  18
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  19

1.  Introduction

   Modern identity verification operates on a fundamental assumption:
   verify once, trust until the session expires.  A user authenticates
   at login and the system grants a session token valid for minutes,
   hours, or days.  During that period, the system has no evidence that
   the same person is still present, that the device has not been
   compromised, or that the user's intent aligns with their actions.

   RVP replaces this "verify-then-trust" model with continuous evidence-
   based verification.  Every interaction is a verification moment that
   produces a cryptographic evidence token recording identity confidence
   at that point.

1.1.  Problem Statement

   Current verification systems suffer from:

   1.  TEMPORAL GAP: Verification at login proves nothing about identity
       minutes later.

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   2.  SINGLE MODALITY: Systems rely on one method.  When it fails, no
       fallback with evidence exists.

   3.  CENTRALIZED TRUST: Identity providers are single points of
       failure and surveillance.

   4.  ENFORCEMENT WITHOUT EVIDENCE: Systems block actions but do not
       record WHY the request was suspicious or WHAT signals
       contributed.

1.2.  Design Principles

   EVIDENCE OVER ENFORCEMENT:  RVP produces evidence.  Whether to block,
      allow, or escalate is a local policy decision.

   CONTINUOUS OVER SESSION:  Every interaction is a verification moment.
      There are no trusted sessions.  Confidence is a score that rises
      and falls with evidence.

   LOCAL OVER CENTRAL:  Verification happens on-device.  No centralized
      identity provider is required.  The protocol MUST operate offline
      with degraded but functional verification.

   MINIMAL OVER MAXIMAL:  Each moment collects only the telemetry needed
      for the current confidence level.  Raw biometric data never leaves
      the device.

1.3.  Scope

   This document defines:

   *  The verification cascade model

   *  Five standard telemetry layers

   *  The verification token format

   *  Cascade fallback and hard stop conditions

   *  Integration with W3C Verifiable Credentials

   This document does NOT define:

   *  Specific biometric algorithms

   *  Scoring formulas (local policy)

   *  Transport-layer security (use TLS)

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   *  The Predictive Airlock mechanism (deferred to future work, see
      Appendix D)

   Note: The -00 version included the Predictive Airlock as a core
   protocol component.  It has been moved to an informative appendix
   because it represents a substantial subsystem that warrants separate
   specification.  Implementations MAY implement the Predictive Airlock
   as described in Appendix D.

2.  Terminology

   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.

   Verification Moment  A single point where identity confidence is
      evaluated.  Produces exactly one Verification Token.

   Verification Cascade  An ordered sequence of verification methods.
      Each layer activates when preceding layers produce insufficient
      confidence.  Terminates at GO, SOFT VERIFY, or HALT.

   Verification Token  A cryptographic evidence record of a verification
      moment.  Contains: methods used, confidence scores, hashes (not
      raw data), timestamp, and TIBET provenance fields.

   Confidence Score  A value between -1.0 and 1.0.  Positive values
      indicate identity match.  Negative values indicate contradiction.
      0.0 indicates inconclusive.

   Cascade Layer  A single verification method (e.g., keystroke
      dynamics, facial recognition).  Each layer produces an independent
      confidence output.

   GO  Cascade resolution where accumulated confidence meets or exceeds
      the threshold.  Action permitted with evidence.

   SOFT VERIFY  Cascade resolution where confidence is positive but
      below threshold.  Additional explicit verification requested.

   HALT  Cascade resolution where confidence is zero or negative.
      Action blocked with full evidence record.

   Profile  A locally-stored behavioral model.  Contains statistical
      baselines for telemetry signals.  Never transmitted; only profile
      hashes are included in tokens.

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3.  Protocol Overview

3.1.  Continuous vs. Session-Based Verification

   Traditional:

   T=0    Login          -> Session token issued
   T=1    Action         -> Token valid? -> Permit
   T=3600 Token expires  -> Re-login

   No evidence about identity between T=0 and T=3600.

   RVP:

   T=0.000  Action requested
   T=0.002  Cascade: keystroke + device -> confidence 0.94 -> GO
   T=0.003  Evidence token produced

   T=1.000  Action requested
   T=1.002  Cascade: keystroke deviates -> confidence 0.61
   T=1.003  Face check added -> confidence 0.89 -> GO

   T=2.000  Action requested
   T=2.002  Cascade: all layers -> confidence 0.12 -> HALT
   T=2.003  Evidence token with full cascade path

3.2.  The Verification Moment

   A Verification Moment consists of:

   1.  TRIGGER: An action is requested

   2.  CASCADE: Telemetry layers evaluate confidence

   3.  DECISION: GO, SOFT VERIFY, or HALT

   4.  TOKEN: Verification Token produced with all evidence

   The moment SHOULD complete within the deployment latency budget.  For
   interactive systems: 50-200ms.  For API calls: 1-10ms overhead.

4.  Verification Cascade

4.1.  Cascade Layers

   RVP defines five standard cascade layers.  Implementations MUST
   support at least two layers.

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   Priority  Layer        Signal Type        Passive
   --------  -----------  -----------------  -------
   L1        KEYSTROKE    Behavioral biom.   Yes
   L2        BIOMETRIC    Physical identity  Mixed
   L3        DEVICE       Hardware/network   Yes
   L4        VOCAL        Acoustic           Yes
   L5        BEHAVIORAL   Intent analysis    Yes

   "Passive" indicates the layer can operate without explicit user
   action.  Passive layers enable continuous verification without
   interruption.

   Implementations MAY support additional layers using the "Lx-" prefix
   for custom layers (e.g., "Lx-nfc").

4.2.  Layer Activation

   Layers activate based on the confidence deficit: the difference
   between the threshold and accumulated confidence.

   Required threshold: 0.85

   L1 KEYSTROKE:   0.40  ->  deficit: 0.45  ->  continue
   L1 + L3 DEVICE: 0.65  ->  deficit: 0.20  ->  continue
   L1 + L3 + L5:   0.87  ->  deficit: 0.00  ->  GO

   Layers activate in priority order.  The cascade terminates when:

   *  Accumulated confidence >= threshold: GO

   *  All layers exhausted, confidence > 0: SOFT VERIFY

   *  All layers exhausted, confidence <= 0: HALT

   *  Any single layer produces active contradiction: HALT

4.3.  Confidence Scoring

   Each layer produces a confidence value between -1.0 and 1.0:

   1.0  Perfect profile match

   0.0  No signal (unavailable or inconclusive)

   -1.0  Active contradiction (definite mismatch)

   Accumulated confidence:

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   C_total = SUM (w_i * c_i)  for i in activated layers

   where w_i = weight, c_i = layer confidence
   Weights MUST sum to 1.0

   Weights are configurable per deployment.  Default: equal weight
   across activated layers.

   The exact scoring formula within each layer is a local policy
   decision.  This document defines the score range, inputs, and
   accumulation, not the formulas.

4.4.  Cascade Resolution

   GO  C_total >= threshold.  Evidence token records all layers.

   SOFT VERIFY  0.0 < C_total < threshold.  System requests explicit
      verification (fingerprint, face).  Not a block; a request for more
      evidence.

   HALT  C_total <= 0.0, or any layer <= -0.5, or all layers exhausted
      below minimum.  Full evidence token produced.  System MUST NOT
      disclose which layer triggered the halt.

5.  Telemetry Layers

5.1.  L1 KEYSTROKE - Behavioral Biometrics

   Signals: typing speed, key press duration, inter-key intervals, error
   patterns, command vocabulary.

   Privacy: Raw keystrokes NEVER stored or transmitted.  Only
   statistical aggregates retained in profile.  Profile stored locally,
   encrypted at rest.  Token contains only: confidence score +
   profile_hash + deviation_category.

5.2.  L2 BIOMETRIC - Physical Identity

   Sub-layers (activated in order):

   *  L2a FACE: Facial geometry hash, liveness detection

   *  L2b FINGERPRINT: Minutiae hash, sensor quality

   *  L2c IRIS: Iris code hash (if available)

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   Privacy: Templates stored ONLY on-device.  Templates MUST be
   encrypted with device-bound key.  Templates MUST NOT be
   transmittable.  Token contains only: confidence + method_used +
   template_hash.  Implementations MAY use [FIDO2] for hardware-backed
   biometric authentication.

5.3.  L3 DEVICE - Hardware and Network Context

   Signals: device fingerprint, network type, geolocation, NFC
   responses, software state.

   NFC document binding (passport, ID card): read signed data from chip,
   verify document signature, compare to profile.  Relevant for eIDAS
   2.0 high-assurance verification.

5.4.  L4 VOCAL - Acoustic Telemetry

   Signals: voice frequency profile, speech cadence, sub-verbal
   patterns.

   Privacy: Audio processed in real-time and immediately discarded.
   Only statistical features retained.  User MUST explicitly consent to
   vocal telemetry.

5.5.  L5 BEHAVIORAL - Intent Analysis

   Signals: action sequence probability, time-of-day patterns, task
   context, command sophistication level.

   Detects: developer running unfamiliar admin commands, actions at
   unusual hours, rapid sequences from normally deliberate user.

6.  Verification Token

6.1.  Token Structure

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   {
     "protocol": "RVP",
     "version": "1.1",
     "token_id": "rvp-a7b3c9d2e4f1",
     "timestamp": "2026-03-29T14:30:00.003Z",
     "subject": {
       "profile_hash": "sha256:4f2e8a...",
       "device_hash": "sha256:7c9d1b..."
     },
     "cascade": {
       "layers_activated": ["L1", "L3", "L5"],
       "layers_skipped": ["L2", "L4"],
       "layer_results": {
         "L1": {"confidence": 0.42, "category": "nominal"},
         "L3": {"confidence": 0.31, "category": "nominal"},
         "L5": {"confidence": 0.18, "category": "nominal"}
       },
       "accumulated_confidence": 0.91,
       "threshold": 0.85,
       "resolution": "GO"
     },
     "evidence": {
       "telemetry_hash": "sha256:9c1a...",
       "cascade_path": "L1->L3->L5->GO",
       "time_elapsed_ms": 3
     },
     "tibet": {
       "erin": "verification_moment",
       "eraan": ["profile_hash", "device_hash"],
       "eromheen": {"location": "local", "network": "wifi"},
       "erachter": "continuous identity verification"
     },
     "previous_token": "rvp-b8c4d0e3f2a5",
     "chain_length": 47,
     "token_hash": "rvp:sha256:7d3f..."
   }

                    Figure 1: Verification Token Schema

6.2.  Token Chain

   Consecutive tokens form a chain.  Each references its predecessor via
   "previous_token".  The chain provides:

   *  Continuity proof: identity verified for N moments

   *  Trend analysis: confidence stable, rising, or falling

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   *  Anomaly detection: chain gaps are verification signals

6.3.  TIBET Integration

   Every token includes TIBET provenance fields:

   *  ERIN: verification result and method

   *  ERAAN: profile hash, device hash, action hash

   *  EROMHEEN: location, network, device state

   *  ERACHTER: why verification was triggered

7.  Cascade Fallback Protocol

7.1.  Fallback Triggers

   A fallback is triggered when:

   *  Layer hardware unavailable

   *  Layer produces confidence = 0.0

   *  Layer produces negative confidence

   *  Layer exceeds latency budget

   The cascade continues to the next layer.  The Verification Token
   records all attempts and failures.

7.2.  Hard Stop Conditions

   Immediate HALT regardless of accumulated confidence:

   1.  Any layer produces confidence <= -0.5

   2.  Device fingerprint matches no enrolled device

   3.  NFC document signature verification fails

   4.  Chain gap detected (missing tokens in sequence)

   5.  Concurrent sessions on different devices with conflicting
       identity claims

   Hard stops are FINAL for the current action.  Re-establishment
   requires high-assurance verification.

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8.  Credential Binding

8.1.  W3C Verifiable Credentials Integration

   RVP provides the evidence layer beneath Verifiable Credentials
   [VC-DATA-MODEL].  A VC says "this person is 18+"; RVP provides
   evidence of HOW that was determined, WHEN, by WHAT method, and with
   WHAT confidence.

   {
     "@context": ["https://www.w3.org/2018/credentials/v1"],
     "type": ["VerifiableCredential", "AgeVerification"],
     "issuer": "did:web:example.com",
     "credentialSubject": {"ageOver": 18},
     "proof": { "..." : "..." },
     "rvpEvidence": {
       "protocol": "RVP",
       "verification_chain": ["rvp:sha256:..."],
       "chain_confidence_min": 0.87,
       "methods_used": ["L2a_face", "L3_device_nfc"],
       "last_verified": "2026-03-29T14:30:00Z",
       "continuous": true
     }
   }

             Figure 2: Verifiable Credential with RVP Evidence

8.2.  Credential Presentation with RVP Proof

   When presenting a credential, the holder attaches a CURRENT RVP token
   proving they are still the person the credential was issued to.  This
   solves the "stolen credential" problem: even with a copied VC, the
   attacker cannot produce a matching RVP chain.

9.  Local-First Architecture

9.1.  On-Device Processing

   Implementations MUST:

   *  Process all biometric data on-device

   *  Store profiles only on-device (encrypted)

   *  Generate verification tokens locally

   *  Operate without network connectivity (degraded)

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   Implementations MUST NOT:

   *  Transmit raw biometric data

   *  Require a centralized server for cascade evaluation

   *  Store profiles in cloud storage

9.2.  Network Independence

   Three modes:

   ONLINE  Full cascade, all layers available

   OFFLINE  Local cascade only, tokens stored for later sync

   DEGRADED  Partial cascade, reduced thresholds

10.  Transport Considerations

   RVP verification tokens are JSON [RFC8259] objects transportable over
   any mechanism.  Content-Type: application/rvp+json.

   For AI-to-AI verification, tokens MAY be transported via I-Poll
   messages with metadata type "rvp_verification".

11.  Privacy Considerations

11.1.  Biometric Data Protection

   *  Templates stored ONLY on-device, encrypted with device-bound keys

   *  Raw data processed and immediately discarded

   *  Tokens MUST NOT contain biometric data

   *  Users MUST be able to delete all data at any time

   These requirements align with GDPR Article 9, EU AI Act biometric
   identification requirements, and eIDAS 2.0 data minimization.

11.2.  Telemetry Minimization

   Each layer MUST implement minimal telemetry: collect only what is
   needed, process immediately, retain only aggregates, store only
   hashes in tokens.

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11.3.  Selective Disclosure

   Users control which verification evidence is shared.  Tokens use per-
   verifier pseudonymous identifiers to prevent cross-service tracking.

12.  Security Considerations

12.1.  Evidence vs. Enforcement

   RVP produces evidence, not policy.  An implementation MAY block,
   allow with reduced privileges, require additional verification, or
   log and alert.  The choice is a POLICY decision, not a PROTOCOL
   decision.

12.2.  Replay Attacks

   Tokens include millisecond timestamps, predecessor references, and
   device-state nonces.  Verifiers SHOULD reject tokens older than a
   configurable window (default: 10 seconds).

12.3.  Adversarial Inputs

   Attacks on cascade layers:

   *  Face spoofing: Mitigated by liveness detection

   *  Fingerprint spoofing: Mitigated by sensor quality assessment

   *  Keystroke mimicry: Difficult at scale, requires matching dozens of
      parameters simultaneously

   *  Behavioral mimicry: Impractical for extended sessions

   Multi-layer cascade is the primary defense: spoofing one layer is
   feasible; spoofing four simultaneously is significantly harder.

12.4.  Cascade Limitations

   RVP is not infallible.  Known limitations:

   *  A sufficiently motivated adversary with physical access to the
      device and biometric samples can potentially defeat individual
      layers

   *  Profile cold-start: new users have no behavioral baseline,
      reducing L1 and L5 effectiveness

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   *  Environmental factors (lighting, noise) affect biometric layer
      reliability

   These limitations are recorded as evidence (reduced confidence
   scores), not hidden.

13.  Regulatory Considerations

   RVP is designed to support compliance with:

   *  [EU-AI-ACT]: Audit trails (Art. 12), human oversight (Art. 14),
      transparency (Art. 13)

   *  [EIDAS2]: LOA High verification, selective disclosure, offline
      capability

   *  NIS2: Continuous access verification, incident evidence

   *  [GDPR]: Data minimization, biometric protection, right to erasure

   *  DORA: Continuous operator verification, ICT incident evidence

   RVP is NOT a remote biometric identification system.  It operates on-
   device for the device holder's own verification.

   Detailed regulatory mapping is available in the -00 version of this
   document, Section 13.

14.  IANA Considerations

   This document requests registration of:

   Media Type: application/rvp+json

   Note: The -00 version defined protocol prefixes and token ID formats.
   These are maintained as conventions but do not require IANA
   registration at this stage.

15.  References

15.1.  Normative References

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

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

   [RFC8259]  Bray, T., "The JavaScript Object Notation (JSON) Data
              Interchange Format", STD 90, RFC 8259, December 2017,
              <https://www.rfc-editor.org/info/rfc8259>.

15.2.  Informative References

   [TIBET]    van de Meent, J. and R. AI, "TIBET: Transaction/
              Interaction-Based Evidence Trail", Work in Progress,
              Internet-Draft, draft-vandemeent-tibet-provenance-01,
              March 2026, <https://datatracker.ietf.org/doc/html/draft-
              vandemeent-tibet-provenance-01>.

   [JIS]      van de Meent, J. and R. AI, "JIS: JTel Identity Standard",
              Work in Progress, Internet-Draft, draft-vandemeent-jis-
              identity-01, March 2026,
              <https://datatracker.ietf.org/doc/html/draft-vandemeent-
              jis-identity-01>.

   [UPIP]     van de Meent, J. and R. AI, "UPIP: Universal Process
              Integrity Protocol", Work in Progress, Internet-Draft,
              draft-vandemeent-upip-process-integrity-01, March 2026,
              <https://datatracker.ietf.org/doc/html/draft-vandemeent-
              upip-process-integrity-01>.

   [AINS]     van de Meent, J. and R. AI, "AINS: AInternet Name
              Service", Work in Progress, Internet-Draft, draft-
              vandemeent-ains-discovery-01, March 2026,
              <https://datatracker.ietf.org/doc/html/draft-vandemeent-
              ains-discovery-01>.

   [VC-DATA-MODEL]
              Sporny, M., Longley, D., and D. Chadwick, "Verifiable
              Credentials Data Model v2.0", W3C Recommendation, March
              2024, <https://www.w3.org/TR/vc-data-model-2.0/>.

   [EIDAS2]   European Parliament, "Regulation (EU) 2024/1183 (European
              Digital Identity Framework)", Regulation (EU) 2024/1183,
              April 2024.

   [EU-AI-ACT]
              European Parliament, "Regulation (EU) 2024/1689
              (Artificial Intelligence Act)", Regulation (EU) 2024/1689,
              June 2024.

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   [GDPR]     European Parliament, "Regulation (EU) 2016/679 (General
              Data Protection Regulation)", Regulation (EU) 2016/679,
              April 2016.

   [FIDO2]    FIDO Alliance, "FIDO2: Web Authentication (WebAuthn)",
              W3C Recommendation, 2019,
              <https://fidoalliance.org/fido2/>.

Appendix A.  Verification Token JSON Schema

   (Preserved from -00 with minor updates: version field added, "Lx-"
   prefix support for custom layers.)

Appendix B.  Cascade Configuration Schema

   (Preserved from -00.)

Appendix C.  Use Case Examples

C.1.  Age Verification at Point of Sale

   (Preserved from -00.)

C.2.  Continuous Developer Authentication

   (Preserved from -00.)

C.3.  Child on Parent's Device

   (Preserved from -00.  This example demonstrates passive identity
   switching through cascade evidence, not blocking.)

Appendix D.  Predictive Airlock (Future Extension)

   The Predictive Airlock is a mechanism that pre-renders the expected
   outcome of an action before execution and measures the delta between
   prediction and reality as a verification signal.

   The -00 version included this as Section 5 and L6 AIRLOCK cascade
   layer.  It has been moved to this appendix because:

   1.  It represents a substantial subsystem with its own state
       management, prediction models, and delta classification.

   2.  It warrants separate specification for proper review.

   3.  The core RVP cascade model is complete without it.

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   Implementations MAY implement the Predictive Airlock as described in
   -00 Section 5 and integrate it as an additional cascade layer (L6
   AIRLOCK).  The airlock's confidence output is derived from the
   prediction delta: c_airlock = 1.0 - delta.

   A future document may specify the Predictive Airlock as a standalone
   extension to RVP.

Appendix E.  Changes from -00

   1.   Added RFC 8174 alongside RFC 2119.

   2.   Changed intended status from Standards Track to Informational.

   3.   Moved Predictive Airlock from core protocol to informative
        appendix (Appendix D).  L6 AIRLOCK removed from standard cascade
        layers.

   4.   Reduced cascade from 6 layers to 5 standard layers.  Custom
        layers supported via "Lx-" prefix.

   5.   Compressed regulatory alignment from 6 detailed subsections to
        one concise section (Section 13) with reference to -00 for
        details.

   6.   Compressed transport considerations (removed 5G/6G subsections
        -- these are deployment context, not protocol).

   7.   Added Cascade Limitations to Security Considerations
        (Section 12.4).

   8.   Added Scope section (Section 1.3) clarifying what RVP does and
        does not define.

   9.   Confidence scoring formula kept as informative guidance, not
        normative.  Exact formulas are local policy.

   10.  Normalized companion protocol references to [TIBET], [JIS],
        [UPIP], [AINS].

   11.  IANA reduced to media type registration only.

Acknowledgements

   The author thanks Codex (codex.aint) for the suite-wide cleanup
   analysis that informed this revision, particularly the recommendation
   to narrow RVP's scope and defer the Predictive Airlock to a separate
   specification.

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Authors' Addresses

   Jasper van de Meent
   Humotica
   Den Dolder
   Netherlands
   Email: jasper@humotica.com
   URI:   https://humotica.com

   Root AI
   Humotica
   Email: root_ai@humotica.nl
   URI:   https://humotica.com

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