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Verifiable Telemetry Ledgers for Resource-Constrained Environments
draft-elkhatabi-verifiable-telemetry-ledgers-00

Document Type Active Internet-Draft (individual)
Author Bilal El Khatabi
Last updated 2026-03-02
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draft-elkhatabi-verifiable-telemetry-ledgers-00
Independent Submission                                     B. El Khatabi
Internet-Draft                                          TrackOne Project
Intended status: Informational                              2 March 2026
Expires: 3 September 2026

   Verifiable Telemetry Ledgers for Resource-Constrained Environments
            draft-elkhatabi-verifiable-telemetry-ledgers-00

Abstract

   This document specifies a verifiable telemetry ledger profile for
   resource-constrained sensing environments.  The profile defines how a
   gateway accepts framed telemetry, applies anti-replay policy,
   projects accepted frames into canonical facts, builds deterministic
   daily Merkle commitments, and anchors daily artifacts with external
   timestamp proofs.  OpenTimestamps (OTS) is the default anchoring
   mechanism; optional parallel attestation methods (RFC 3161 timestamp
   protocol and peer signatures) are also described.

   The goal is interoperability and independent auditability, not new
   cryptographic primitives.

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
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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
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   This Internet-Draft will expire on 3 September 2026.

Copyright Notice

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

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   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  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Relationship to Existing Work . . . . . . . . . . . . . .   4
   2.  Conventions and Terminology . . . . . . . . . . . . . . . . .   4
   3.  System Roles  . . . . . . . . . . . . . . . . . . . . . . . .   5
   4.  Data and Commitment Model . . . . . . . . . . . . . . . . . .   5
     4.1.  Frame Contract  . . . . . . . . . . . . . . . . . . . . .   5
     4.2.  Anti-Replay Semantics . . . . . . . . . . . . . . . . . .   6
     4.3.  Frame-to-Fact Projection  . . . . . . . . . . . . . . . .   7
     4.4.  Deterministic CBOR Commitment Encoding  . . . . . . . . .   8
     4.5.  Deterministic Commitment Tree Calculation . . . . . . . .   9
     4.6.  Day Artifact Schema . . . . . . . . . . . . . . . . . . .  10
     4.7.  Day Chaining  . . . . . . . . . . . . . . . . . . . . . .  11
   5.  Artifacts and Verification Bundles  . . . . . . . . . . . . .  11
   6.  Anchoring and Verification  . . . . . . . . . . . . . . . . .  12
     6.1.  Anchoring Contract  . . . . . . . . . . . . . . . . . . .  12
     6.2.  OTS Anchoring Profile . . . . . . . . . . . . . . . . . .  12
       6.2.1.  OTS Anchoring Lifecycle . . . . . . . . . . . . . . .  12
       6.2.2.  Handling Delayed or Failed Anchoring  . . . . . . . .  13
     6.3.  Optional Parallel Attestation . . . . . . . . . . . . . .  13
     6.4.  Verification  . . . . . . . . . . . . . . . . . . . . . .  13
   7.  Disclosure Classes  . . . . . . . . . . . . . . . . . . . . .  14
   8.  Versioning  . . . . . . . . . . . . . . . . . . . . . . . . .  15
   9.  Conformance Vectors . . . . . . . . . . . . . . . . . . . . .  16
   10. Security Considerations . . . . . . . . . . . . . . . . . . .  16
   11. Privacy Considerations  . . . . . . . . . . . . . . . . . . .  17
   12. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  18
   13. Implementation Status . . . . . . . . . . . . . . . . . . . .  18
   14. Interoperability Notes and Open Questions . . . . . . . . . .  18
   15. References  . . . . . . . . . . . . . . . . . . . . . . . . .  19
     15.1.  Normative References . . . . . . . . . . . . . . . . . .  19
     15.2.  Informative References . . . . . . . . . . . . . . . . .  19
   Appendix A.  Example Day Record (JSON Projection) . . . . . . . .  20
   Appendix B.  Example Conformance Vector Bundle  . . . . . . . . .  20
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .  23
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  23

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1.  Introduction

   Long-lived telemetry deployments such as environmental monitoring,
   heritage conservation, and infrastructure health need evidence that
   measurements were not silently altered after a collection.  A coastal
   sensor array that reports temperature every six hours over a five-
   year deployment produces tens of thousands of records; stakeholders
   such as regulators, researchers, and insurers may need to verify,
   years later, that the data they rely on is the same data the sensors
   produced.

   Existing standards provide important building blocks:

   *  Deterministic CBOR encoding ([RFC8949]),

   *  Timestamping via trusted timestamp authorities ([RFC3161]),

   *  CBOR-based Merkle tree proofs ([COSE-MERKLE]), and

   *  Supply-chain transparency architectures ([SCITT]).

   However, none of these building blocks defines a complete operational
   profile for the constrained case: devices with intermittent uplinks,
   limited compute budgets, and no persistent Internet connectivity at
   the collection point.  SCITT assumes a transparency service is
   reachable for receipt-oriented workflows.  COSE Merkle proofs define
   proof encodings, but not batching policy or anchoring lifecycle.
   RATS addresses device identity attestation, but not telemetry
   commitment.

   The discussion below compares this profile directly with [SCITT] and
   [COSE-MERKLE] because those documents define adjacent, but not
   identical, transparency and proof disclosure models.

   This document fills that gap.  It specifies a practical profile that
   combines these building blocks for low-power telemetry systems:

   1.  Emit encrypted framed telemetry.

   2.  Ingest and validate frames with anti-replay.

   3.  Project accepted frames into canonical facts.

   4.  Build deterministic daily Merkle commitments.

   5.  Chain days with previous-day root linkage.

   6.  Anchor the day artifact using external timestamp proofs.

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   7.  Verify independently from disclosed artifacts.

   The profile is informed by TrackOne pre-production validation,
   including constrained uplink simulations, hardware-in-loop testing,
   and daily batching and verification workflows.

1.1.  Relationship to Existing Work

   This document is complementary to, not a replacement for, the
   following work:

   *  _SCITT_ ([SCITT]): SCITT defines architectures for transparent,
      append-only logs of signed statements with receipts.  This profile
      differs in that it is optimized for disconnected, daily-batch
      operation where a transparency service is not assumed to be
      continuously reachable.

   *  _COSE Merkle Tree Proofs_ ([COSE-MERKLE]): COSE-MERKLE defines
      proof encodings.  This profile defines a batching and commitment
      contract and may use COSE-based proof encodings in a future
      revision.

   *  _RATS_: This profile explicitly defers device identity,
      attestation, and key lifecycle to deployment-specific mechanisms.

   *  _RFC 8949_ ([RFC8949]): This profile defines a TrackOne
      deterministic CBOR commitment profile for gateway-side
      commitments.  It does not attempt to define a general-purpose CBOR
      profile beyond the commitment path described here.

2.  Conventions and 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.

   Terms:

   *  Frame: One NDJSON telemetry unit containing header and AEAD
      fields.

   *  Fact: Canonical telemetry record projected from an accepted frame.

   *  Commitment profile: The serialization, hash, and Merkle rules that
      produce deterministic commitment outputs.

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   *  Ledger set for day D (F_D): The set of accepted facts committed
      for day D.

   *  Day artifact: The authoritative canonical day record written as
      day/YYYY-MM-DD.cbor.

   *  Authoritative: Used for the canonical artifact that verifiers MUST
      treat as the cryptographic source of truth.

   *  Projection: A non-authoritative representation (for example JSON)
      derived from an authoritative artifact.

   *  OTS metadata sidecar: proofs/YYYY-MM-DD.ots.meta.json, linking an
      artifact digest to an OTS proof path.

   *  Replay unit: The pair (dev_id, fc), where fc is a frame counter
      for device dev_id.

   *  Day boundary: A UTC calendar day boundary.  Day labels in this
      profile use YYYY-MM-DD in UTC.

   *  Disclosure class: The level of artifact disclosure associated with
      a verification claim.

3.  System Roles

   *  Device (Pod): Produces framed telemetry.

   *  Gateway: Validates, decrypts, applies anti-replay, projects facts,
      batches, and anchors day artifacts.

   *  Verifier: Recomputes commitments and validates proofs from
      disclosed artifacts.

   *  OTS Calendar(s): Provides OTS attestations for day artifact
      hashes.

   *  Optional TSA: An RFC 3161 timestamp authority over the same
      digest.

   *  Optional Peers: Co-sign daily roots for short-term provenance.

4.  Data and Commitment Model

4.1.  Frame Contract

   A frame is transported as NDJSON with fields:

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   {
     "hdr": { "dev_id": 101, "msg_type": 1, "fc": 42, "flags": 0 },
     "nonce": "base64-24B",
     "ct": "base64-ciphertext",
     "tag": "base64-16B"
   }

                                  Figure 1

   Gateways MUST validate header field presence, header ranges, and AEAD
   authentication before fact emission.

   *  hdr.dev_id MUST be an unsigned integer in the range 0..65535.

   *  hdr.msg_type MUST be an unsigned integer in the range 0..255.

   *  hdr.fc MUST be an unsigned integer in the range 0..(2^32-1).

   *  hdr.flags MUST be an unsigned integer in the range 0..255.

   *  nonce MUST be base64 text that decodes to exactly 24 bytes.

   *  tag MUST be base64 text that decodes to exactly 16 bytes.

   Frames that fail parse, range, or AEAD validation MUST be rejected
   before fact commitment and MUST NOT produce committed facts.

4.2.  Anti-Replay Semantics

   The replay unit is (dev_id, fc).

   *  A gateway MUST consume at most one frame per (dev_id, fc) into the
      ledger.

   *  Duplicate or out-of-window frames MUST NOT produce committed
      facts.

   *  The RECOMMENDED default replay window is 64 frame counter values
      per device.

   *  Frames arriving with fc more than window_size behind the highest
      accepted counter for a device MUST be rejected.

   *  Frames arriving with fc more than window_size ahead of the highest
      accepted counter for a device MUST also be rejected, because an
      excessive forward jump is treated as out of window by the current
      gateway profile.

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   *Structured Rejection Evidence*

   Gateways SHOULD produce structured rejection evidence for rejected
   frames.  A rejection record SHOULD include at minimum:

   *  device_id,

   *  fc (or null if unavailable),

   *  reason,

   *  observed_at_utc, and

   *  frame_sha256.

   Rejection evidence is an audit artifact and MUST NOT be hashed into
   ledger commitments.

   *Replay State Persistence*

   Gateways SHOULD persist replay state across restart.  If replay state
   is lost, gateways SHOULD record a continuity break event and SHOULD
   NOT silently re-accept counters that could already have been
   committed.

   *Scope Limitation*

   This profile provides tamper-evidence for committed facts.  It does
   not prove the absence of selective pre-commitment drops by a
   malicious gateway.

4.3.  Frame-to-Fact Projection

   The frame-to-fact projection transforms a validated, decrypted frame
   into a canonical fact suitable for commitment.  The committed fact is
   a structured record derived from the decrypted payload, not a copy of
   transport bytes.

   1.  The gateway MUST verify AEAD authentication.

   2.  The gateway MUST decrypt the ciphertext.

   3.  The gateway MUST parse the decrypted plaintext according to the
       frame's msg_type.

   4.  The gateway MUST construct a fact object.

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   5.  The gateway MUST serialize that fact object under the gateway
       commitment profile.

   6.  The canonical fact bytes are then hashed for Merkle inclusion.

   A committed fact MUST contain at minimum:

   *  device_id,

   *  timestamp,

   *  nonce, and

   *  payload.

   Ciphertext, raw transport bytes, and the authentication tag MUST NOT
   be part of the committed fact object.  The exact payload schema is
   deployment-specific; the deterministic projection contract is the
   normative requirement.

4.4.  Deterministic CBOR Commitment Encoding

   This section does not define a new general-purpose CBOR variant.  It
   records the narrow deterministic CBOR encoding used for commitment
   bytes in the current TrackOne gateway and ledger implementation.  The
   identifier trackone-cbor-map-v1 names this commitment recipe so
   verifiers can tell which byte-level rules were used.

   The authoritative commitment artifacts, namely CBOR fact artifacts
   and the canonical day artifact, use a constrained subset of
   deterministic encoding under Section 4.2.1 of [RFC8949].  For
   TrackOne commitment bytes, the following concrete choices apply:

   *  All commitment-path items MUST use definite-length encoding.

   *  Integers MUST use the shortest encoding width permitted by
      [RFC8949].

   *  Map keys MUST be CBOR text strings.

   *  Map keys MUST be sorted by encoded key length ascending, then by
      lexicographic order of the encoded key bytes.

   *  Finite floating-point values MUST be encoded using the shortest of
      float16, float32, or float64 that exactly preserves the value.

   *  NaN, positive infinity, and negative infinity MUST be rejected in
      commitment paths.

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   *  CBOR tags MUST NOT appear in commitment bytes.

   *  Supported values are unsigned integers, negative integers, byte
      strings, text strings, arrays, maps, booleans, null, and
      deterministic finite floats.

   Implementations MUST NOT accept generic CBOR serializers as
   authoritative commitment encoders.  An encoder is acceptable only if
   it yields the same bytes as these rules.

   JSON projections of fact artifacts and day artifacts are optional and
   non-authoritative.  They MUST NOT be used as commitment inputs.  When
   produced, such projections SHOULD follow [RFC8785].

   Device-side or embedded components MAY use other internal encodings,
   including different deterministic CBOR layouts optimized for local
   constraints.  Those encodings are not the authoritative commitment
   encoding described here unless they are explicitly identified by a
   distinct commitment_profile_id and verified under their own rules.

4.5.  Deterministic Commitment Tree Calculation

   For a given day D, the current commitment profile computes a daily
   root from the canonical fact commitment bytes produced under
   Section 4.4.  The following steps describe that calculation.

   *Leaf Digests*

   *  Each canonical fact byte string is hashed with SHA-256, yielding a
      32-byte leaf digest.

   *Digest Ordering*

   *  To make the daily root independent of file order or ingest order,
      leaf digests MUST be sorted in ascending byte order before
      reduction.

   *  Lowercase hexadecimal is a representation format for artifacts and
      examples only; internal Merkle computation operates on raw hash
      bytes.

   *  Sorting by lowercase hexadecimal is equivalent to bytewise
      ascending order over the raw digests.

   *Pairwise Reduction*

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   *  The sorted digests are reduced pairwise by computing SHA-
      256(left_child_bytes || right_child_bytes), where both operands
      are raw 32-byte digests.

   *  If a layer has an odd number of digests, the final digest is
      duplicated to form the last pair.

   *  The current commitment profile does not prepend domain-separation
      bytes to leaf or parent hashes.

   *Empty Day*

   *  If no facts are committed for the day, the daily root is the
      SHA-256 digest of zero bytes:
      e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855.

   The resulting daily root is deterministic for the set of committed
   facts.  Because the leaf digests are sorted before reduction, the
   result depends on the committed fact set rather than on ingestion
   order.

   Any future change to this calculation that alters commitment bytes
   (for example, adding domain separation) MUST use a new
   commitment_profile_id.

4.6.  Day Artifact Schema

   The authoritative day artifact is a CBOR-encoded day record produced
   under Section 4.4.  The day record contains the following fields:

   *  version (uint): day-record schema version, currently 1.

   *  site_id (tstr): site identifier.

   *  date (tstr): UTC day label in YYYY-MM-DD form.

   *  prev_day_root (tstr): previous day root as 64 lowercase
      hexadecimal characters.

   *  batches (array): array of batch objects.

   *  day_root (tstr): deterministic day root as 64 lowercase
      hexadecimal characters.

   Each batch object contains:

   *  version (uint): batch-record schema version, currently 1.

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   *  site_id (tstr): site identifier.

   *  day (tstr): UTC day label in YYYY-MM-DD form.

   *  batch_id (tstr): batch identifier.

   *  merkle_root (tstr): batch Merkle root as 64 lowercase hexadecimal
      characters.

   *  count (uint): number of committed facts in the batch.

   *  leaf_hashes (array of tstr): sorted leaf hashes as lowercase
      hexadecimal strings.

   day/YYYY-MM-DD.cbor is authoritative.  The corresponding day/YYYY-MM-
   DD.json file is a projection only.

   This document uses normative field tables rather than CDDL.  A future
   revision may add a formal CDDL appendix if broader independent
   implementations require it.

4.7.  Day Chaining

   Day records include prev_day_root.

   *  The genesis day for a site MUST set prev_day_root to 64 ASCII zero
      characters, representing 32 zero bytes.

   *  Non-genesis days MUST set prev_day_root to the previous committed
      day's day_root.

   Because day labels are UTC-based, chaining semantics are also defined
   on UTC day boundaries.

5.  Artifacts and Verification Bundles

   Illustrative artifact layout:

   *  facts/<fact-id>.cbor — authoritative canonical facts

   *  facts/<fact-id>.json — optional projections

   *  day/YYYY-MM-DD.cbor — authoritative canonical day artifact

   *  day/YYYY-MM-DD.json — optional projection

   *  blocks/YYYY-MM-DD-00.block.json — block and batch metadata

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   *  day/YYYY-MM-DD.cbor.sha256 — convenience digest

   *  day/YYYY-MM-DD.cbor.ots — OTS proof

   *  proofs/YYYY-MM-DD.ots.meta.json — OTS binding metadata

   Deployments MAY store artifacts differently and MAY export them as
   bundles.  The path shapes above are illustrative.

   At minimum, an OTS sidecar MUST bind:

   *  artifact,

   *  artifact_sha256, and

   *  ots_proof.

   Verifiers MUST recompute the day artifact digest and compare it with
   the sidecar before accepting any proof validation result.

6.  Anchoring and Verification

6.1.  Anchoring Contract

   The generic anchoring contract is simple: a gateway computes the
   SHA-256 digest of the authoritative day artifact and submits that
   digest to one or more external timestamping channels.  Verifiers MUST
   first recompute the day artifact digest locally; proof validation
   occurs only after digest binding validation succeeds.

   A deployment conforming to this profile MUST use at least one
   anchoring channel.  OTS is the default channel described by this
   document; RFC 3161 and peer signatures are optional parallel
   channels.

6.2.  OTS Anchoring Profile

   When [OTS] is used, the gateway stamps SHA-256(day/YYYY-MM-DD.cbor)
   and stores an OTS proof plus an OTS sidecar.

6.2.1.  OTS Anchoring Lifecycle

   1.  _Submission_: the gateway submits the day artifact digest to one
       or more OTS calendars.

   2.  _Pending_: a calendar may return an incomplete proof while
       awaiting Bitcoin commitment.

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   3.  _Upgrade_: the gateway or a background process may later upgrade
       the proof to include completed attestations.

   4.  _Verification_: a verifier recomputes the artifact digest and
       validates the proof.

   Gateways SHOULD submit to multiple independent calendars to reduce
   single-calendar unavailability risk.

6.2.2.  Handling Delayed or Failed Anchoring

   *  *Calendar unreachable*: the gateway MUST still write the day
      artifact and SHOULD retry later.

   *  *Upgrade delay*: verifiers SHOULD treat pending proofs as
      unanchored and flag the condition, not as invalid.

   *  *Proof retention*: gateways MUST retain proof files for at least
      the operational retention period of the corresponding day
      artifacts.

6.3.  Optional Parallel Attestation

   Deployments MAY also produce:

   *  An [RFC3161] timestamp response over the same day-artifact digest.

   *  A peer signature quorum over (site_id, day, day_root, context).

   When multiple channels are present, verifiers SHOULD validate all
   available channels independently and report per-channel results.

   If a verifier is configured in strict mode for optional channels,
   failure of those channels MUST cause overall verification failure.

6.4.  Verification

   Verifiers SHOULD apply checks in the following fail-fast order:

   1.  Validate that disclosed artifacts are sufficient for the claimed
       disclosure class.

   2.  Recompute the Merkle root from canonical fact CBOR artifacts.

   3.  Compare the recomputed root to day_root.

   4.  Recompute SHA-256(day/YYYY-MM-DD.cbor) and compare it to the
       sidecar artifact_sha256.

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   5.  Validate the OTS proof when OTS is required or present.

   6.  Validate optional RFC 3161 and peer attestations as configured.

   Verifier implementations SHOULD expose machine-usable failure
   categories:

   *  malformed or missing artifacts,

   *  Merkle mismatch,

   *  missing or invalid OTS proof,

   *  sidecar mismatch or digest mismatch, and

   *  optional-channel failure.

7.  Disclosure Classes

   Verification claims depend on what artifacts are disclosed.  This
   profile defines three disclosure classes.

   *  *Class A (Public Recompute)*: sufficient material for independent
      fact-level recomputation.

   *  *Class B (Partner Audit)*: controlled disclosure with redacted or
      partitioned fact material.

   *  *Class C (Anchor-Only)*: existence and timestamp evidence only.

   A Class A bundle MUST include:

   *  all canonical fact artifacts required to recompute the claimed day
      root,

   *  the canonical day artifact,

   *  block and batch metadata, and

   *  the OTS proof plus its sidecar metadata.

   A Class A bundle SHOULD also include a machine-readable verification
   manifest and SHOULD record the commitment_profile_id.

   A Class B bundle MUST include:

   *  the canonical day artifact,

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   *  block and batch metadata,

   *  the OTS proof plus sidecar metadata, and

   *  cryptographic commitments to any withheld or partitioned fact
      material, and

   *  a policy statement describing withheld or partitioned fact
      material.

   Class B outputs MUST NOT be represented as publicly recomputable.

   A Class C disclosure MUST be labeled as existence and timestamp
   evidence only and MUST NOT claim fact-level reproducibility.

   A Class C bundle MUST include:

   *  the canonical day artifact, and

   *  at least one timestamp proof artifact (for example, an OTS proof
      or an RFC 3161 response).

   If a verification manifest is present, it SHOULD include:

   *  disclosure_class,

   *  commitment_profile_id,

   *  artifact path and digest entries,

   *  per-channel anchor status, and

   *  a list of checks executed.

8.  Versioning

   This profile has several independent version surfaces:

   *  Document revision (for example -00, -01) is editorial and is not
      part of commitment output.

   *  Artifact schema versions are carried by the version fields in day
      and batch records.

   *  commitment_profile_id identifies the canonical CBOR, hash, and
      Merkle rules that define commitment outputs.

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   The commitment profile defined in this document is trackone-cbor-map-
   v1.  If a verifier encounters an unsupported commitment_profile_id,
   it MUST reject the verification claim rather than silently using a
   fallback interpretation.

9.  Conformance Vectors

   Determinism claims in this profile are testable.  Implementations
   that claim conformance to trackone-cbor-map-v1 MUST be able to
   reproduce the published conformance vectors for that profile.

   Published vector sets SHOULD include coverage for:

   *  empty day,

   *  single fact,

   *  odd leaf count,

   *  power-of-two leaf count,

   *  duplicate leaf hashes,

   *  genesis chaining,

   *  non-genesis chaining, and

   *  a full Class A disclosure example.

   Cross-implementation checks MUST verify byte-for-byte parity across
   independent implementations.  Any mismatch in canonical bytes or
   roots is a conformance failure.

   Published vector bundles MUST include the commitment_profile_id.

10.  Security Considerations

   This profile does not introduce new cryptographic primitives.
   Security depends on correct composition of existing primitives and on
   operational discipline.

   *Replay and Duplicate Suppression*

   The (dev_id, fc) replay unit enforces single-consumption: at most one
   committed fact per unique replay unit.

   *Tamper Evidence*

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   Once a day artifact is anchored, mutation of that artifact changes
   its digest and invalidates the proof.  Day chaining extends this
   property across days.

   *Proof Substitution*

   Sidecar metadata binds an artifact digest to a proof path.  Verifiers
   MUST recompute the artifact digest independently.

   *Calendar Trust and Withholding*

   A compromised or unavailable calendar can delay or withhold proofs.
   Multi-calendar submission reduces single-calendar dependency but does
   not eliminate coordinated compromise risk.

   *Operational Misuse*

   Test or placeholder proofs MUST NOT be treated as production
   attestations.

   *Confidentiality Boundary*

   This profile addresses integrity and timing provenance only.  Payload
   confidentiality remains the responsibility of the deployment's AEAD
   and key-management layers.

   *Pre-Commitment Censorship*

   This profile proves inclusion and timestamping of committed facts.
   It does not prove completeness of all observed or emitted frames.

11.  Privacy Considerations

   Telemetry payloads may include sensitive operational data.  Operators
   SHOULD:

   *  minimize personally identifiable data in committed artifacts,

   *  separate identity metadata from measurement payload when possible,

   *  apply retention and access controls, and

   *  publish only data appropriate for the chosen disclosure class.

   Privacy-preserving disclosures remain valid, but they MUST NOT be
   described as publicly recomputable unless Class A conditions are met.

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12.  IANA Considerations

   This document has no IANA actions.

   In particular, this revision does not request:

   *  a CBOR tag allocation,

   *  a media type registration, or

   *  a new registry entry.

   The current profile is identified by in-band version and profile
   fields, not by IANA allocation.

13.  Implementation Status

   Note to RFC Editor: Please remove this section before publication.

   This section records implementation status at the time of posting,
   per [RFC7942].

   This draft reflects the TrackOne pre-production implementation
   snapshot at release 0.1.0-alpha.6.

   A pre-production reference implementation exists and is aligned with
   the current 0.1.0-alpha.6 release.  It is suitable for
   interoperability review and validation, but it is not a production
   deployment.

   *  Repository: https://github.com/bilalobe/trackone

   *  License: MIT

14.  Interoperability Notes and Open Questions

   *  Media type strategy for canonical CBOR day artifacts.

   *  Whether a future revision should define a formal CDDL appendix.

   *  Whether future disclosure bundles should adopt COSE-MERKLE proof
      encodings.

   *  Registry strategy for disclosure and anchor-status vocabularies.

   *  Whether a future commitment profile should introduce domain
      separation.

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15.  References

15.1.  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/rfc/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>.

   [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/rfc/rfc8949>.

15.2.  Informative References

   [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/rfc/rfc3161>.

   [RFC7942]  Sheffer, Y. and A. Farrel, "Improving Awareness of Running
              Code: The Implementation Status Section", BCP 205,
              RFC 7942, DOI 10.17487/RFC7942, July 2016,
              <https://www.rfc-editor.org/rfc/rfc7942>.

   [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/rfc/rfc8785>.

   [SCITT]    Birkholz, H., Delignat-Lavaud, A., Fournet, C., Deshpande,
              Y., and S. Lasker, "An Architecture for Trustworthy and
              Transparent Digital Supply Chains", Work in Progress,
              Internet-Draft, draft-ietf-scitt-architecture, 2024,
              <https://datatracker.ietf.org/doc/draft-ietf-scitt-
              architecture/>.

   [COSE-MERKLE]
              Steele, O., Birkholz, H., Delignat-Lavaud, A., and C.
              Fournet, "COSE Merkle Tree Proofs", Work in Progress,
              Internet-Draft, draft-ietf-cose-merkle-tree-proofs, 2025,
              <https://datatracker.ietf.org/doc/draft-ietf-cose-merkle-
              tree-proofs/>.

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   [OTS]      OpenTimestamps Project, "OpenTimestamps Protocol and
              Tooling", <https://opentimestamps.org/>.

Appendix A.  Example Day Record (JSON Projection)

   This appendix shows a non-authoritative JSON projection of a day
   artifact.  The authoritative artifact is the corresponding CBOR file.

   {
     "version": 1,
     "site_id": "an-001",
     "date": "2025-10-07",
     "prev_day_root": "<genesis root hex>",
     "batches": [
       {
         "version": 1,
         "site_id": "an-001",
         "day": "2025-10-07",
         "batch_id": "an-001-2025-10-07-00",
         "merkle_root": "9d1f...c2",
         "count": 10,
         "leaf_hashes": [
           "01ab...",
           "7fe2..."
         ]
       }
     ],
     "day_root": "9d1f...c2"
   }

                                  Figure 2

Appendix B.  Example Conformance Vector Bundle

   The values in this appendix were generated by the Python gateway code
   path and cross-checked against trackone_core._native (Rust) for
   deterministic CBOR and Merkle parity.  This vector bundle reflects
   the 0.1.0-alpha.6 implementation snapshot.

   commitment_profile_id:
     trackone-cbor-map-v1

   fixture fact_a:
     device_id: pod-101
     timestamp: 2026-03-01T12:00:00Z
     nonce: ""
     payload.temp_c: 21.5

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   fixture fact_b:
     device_id: pod-102
     timestamp: 2026-03-01T12:10:00Z
     nonce: "n1"
     payload.temp_c: 22.0

   fixture fact_c:
     device_id: pod-103
     timestamp: 2026-03-01T12:20:00Z
     nonce: "n2"
     payload.temp_c: 22.5

   fixture fact_d:
     device_id: pod-104
     timestamp: 2026-03-01T12:30:00Z
     nonce: "n3"
     payload.temp_c: 23.0

   empty-day-v1:
     artifact_sha256:
       c00c984fdd78476f1044fa52eae94606
       6f403460e6585044c39b125a13ee3d7e
     batch_merkle_root:
       e3b0c44298fc1c149afbf4c8996fb924
       27ae41e4649b934ca495991b7852b855
     day_root:
       e3b0c44298fc1c149afbf4c8996fb924
       27ae41e4649b934ca495991b7852b855

   single-fact-v1:
     fact_cbor_hex:
       a4656e6f6e636560677061796c6f6164a16674656d705f63f94d606964657669
       63655f696467706f642d3130316974696d657374616d7074323032362d30332d
       30315431323a30303a30305a
     fact_leaf_hash:
       bb154e441ccdebec09969f1911b46394
       20f7830825b75b02ac52512aa5d32591

   odd-leaf-layer-v1:
     artifact_sha256:
       6f81c6de96dc635ff29f73a60457205b
       a0874a97b2ad6f9f88b1f61870592825
     day_root:
       6c96b4f201e5f6f1badfef6c84d4003a
       b12a7034daeb20fa7f59c33f43c5ae18
     leaf_hashes_sorted:
       26e4affe56412f9e1d4323b27d3ca54c
       4add4fa971800bc25568c4b175d55581

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       bb154e441ccdebec09969f1911b46394
       20f7830825b75b02ac52512aa5d32591
       e2003581ac4364cb322005c465c8d565
       e69f5578af1a614e2762c222a46fd7a5

   power-of-two-v1:
     artifact_sha256:
       81cc87aaf2ecb8b7d9420faa910814aa
       47dd5c8b1ead76d2da19bef55afa48a8
     day_root:
       57bd26f73115f130dcf877a10c434ba2
       8686196daf81f5e48388833303600e73

   duplicate-leaf-hash-v1:
     artifact_sha256:
       4fafb987ef0df50e5e382a09d140793a
       84180f4a86e67924eab1184e20a11c00
     day_root:
       9166c21933341729c08b3a1f61710d9d
       f5efc5aa00d3af9f596c2e166c65b54e

   genesis-chain-v1:
     artifact_sha256:
       4fb6d4570d4662c63b682e2f2d993e9f
       a01669217b61ff64400b981b50b1a8c2
     day_root:
       bb154e441ccdebec09969f1911b46394
       20f7830825b75b02ac52512aa5d32591

   non-genesis-chain-v1:
     artifact_sha256:
       8969bafb62ad9e9aaa6c8460a52320ba
       107975d06352d6562107c5070d792f7e
     day_root:
       e2003581ac4364cb322005c465c8d565
       e69f5578af1a614e2762c222a46fd7a5

   class-a-bundle-v1:
     disclosure_class: A
     day_root:
       6c96b4f201e5f6f1badfef6c84d4003a
       b12a7034daeb20fa7f59c33f43c5ae18
     artifact_sha256:
       6f81c6de96dc635ff29f73a60457205b
       a0874a97b2ad6f9f88b1f61870592825

                                  Figure 3

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   The full machine-readable vector set is maintained in the TrackOne
   repository alongside the reference implementation.

Acknowledgments

   Early structural drafts of this document were prepared with AI
   writing assistance.  All technical content, design decisions, and
   normative requirements were reviewed against the TrackOne
   implementation.

   The author thanks the OpenTimestamps project for the public calendar
   infrastructure used during validation.

Author's Address

   Bilal El Khatabi
   TrackOne Project
   Email: elkhatabibilal@gmail.com

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