]> Transparency Record Protocol for AI Governance Clearpath Intelligence
pierre.rust@clearpathintel.com
Applications and Real-Time Internet Engineering Task Force AI transparency governance audit This document specifies the Transparency Record Protocol (TRP), an application-layer protocol for propagating AI transparency metadata across distributed systems. TRP enables organizations to maintain cryptographic chain of custody for AI-generated content, enforce governance policies at network boundaries, and provide verifiable audit trails for regulatory compliance.
Introduction The rapid deployment of AI systems across critical infrastructure requires standardized mechanisms for transparency and accountability. Current approaches rely on application-specific logging that cannot be verified across organizational boundaries. The Transparency Record Protocol (TRP) addresses this gap by providing:
  • Cryptographically signed audit trails for AI decisions
  • Zero-trust identity verification using X.509 PKI
  • Network-boundary policy enforcement via inspection headers
  • Extensible metadata for quality metrics and governance frameworks
TRP is designed to integrate with existing HTTP infrastructure through custom headers, requiring no changes to application payloads.
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 when, and only when, they appear in all capitals, as shown here.
Terminology
TRP Record
A JSON document containing transparency metadata for a single request-response cycle or streaming session.
Entity
A service, system, or organization identified by a Decentralized Identifier (DID) and authenticated via X.509 certificate chain.
Processing Step
A single hop in the request processing chain, recorded with timestamp and cryptographic signature.
Composite Confidence
A cumulative trust score that decays as a record propagates across organizational boundaries.
Protocol Overview TRP operates as an overlay protocol on HTTP/1.1 and HTTP/2. Each HTTP request carrying TRP metadata includes:
  1. A compressed context header containing the full TRP record
  2. An uncompressed inspection header for fast firewall decisions
  3. A signature header containing the most recent cryptographic signature
Upon receiving a TRP-enabled request, a compliant service:
  1. Validates the signature chain
  2. Verifies entity identity against allow-lists
  3. Checks security clearance compatibility
  4. Enforces governance requirements
  5. Appends its own processing step and signature
  6. Forwards the updated record
Header Transport TRP-compliant HTTP messages MUST include the following headers:
X-Transparency-Context Contains the Base64-encoded, zstd-compressed JSON TRP record. ]]>
X-Transparency-Protocol Indicates the TRP version.
X-Transparency-Signature Contains the Ed25519 signature of the current record state. ]]>
X-Transparency-Inspection Contains an uncompressed JSON summary for inline firewall evaluation.
Record Structure The TRP record is a JSON object with the following top-level fields:
Record Header
protocol
REQUIRED. String. Must be "TRP/1.1".
id
REQUIRED. String. UUID v4 identifying this record.
correlation_id
OPTIONAL. String. UUID linking related records.
started_at
REQUIRED. String. ISO 8601 timestamp.
validity
OPTIONAL. Object containing freshness constraints.
Entity Context The entity_context object identifies the originating service:
organization
REQUIRED. String. DID of the organization.
service_id
REQUIRED. String. Unique service identifier.
certificate_chain
REQUIRED. Array of Base64-encoded X.509 certificates.
Security Context The security_context object defines access control:
domain
REQUIRED. String. Security domain identifier.
level
REQUIRED. String. Classification level.
previous_level
OPTIONAL. String. Prior classification.
update_reason
OPTIONAL. String. Reason for level change.
Governance Context The governance_context object identifies compliance frameworks:
frameworks_applied
REQUIRED. Array of framework identifiers.
policy_version
REQUIRED. String. Policy version.
compliance_assertions
OPTIONAL. Array of compliance claims.
Signature Chain TRP uses a cumulative signature chain to ensure tamper evidence. Each processing step appends a signature covering:
  1. The hash of all previous content (SHA-256)
  2. The current processing step data
  3. A timestamp
The signature algorithm MUST be Ed25519 as specified in . Signature verification MUST validate the entire chain from origin to the current step. Any invalid signature indicates tampering.
Policy Enforcement TRP-compliant firewalls SHOULD implement the following checks:
Integrity Verification Validate all signatures in the chain.
Freshness Verification Check that validity.expires_at has not passed.
Identity Verification Verify entity_context.organization is in the allow-list.
Clearance Verification Verify security_context.level does not exceed local clearance.
Governance Verification Verify required frameworks are present in governance_context.
Egress Verification Verify destination is in egress_context.authorized_recipients.
Security Considerations
Cryptographic Strength TRP relies on Ed25519 signatures and SHA-256 hashes. These algorithms are considered secure as of this writing.
Replay Attacks The validity.expires_at field provides replay protection. Receivers SHOULD reject records with expired timestamps.
Key Management Entity private keys MUST be stored in hardware security modules (HSMs) or equivalent secure enclaves in production deployments.
Denial of Service Large TRP records may be used for DoS attacks. Implementations SHOULD enforce maximum record sizes (RECOMMENDED: 64KB compressed).
IANA Considerations This document requests registration of the following HTTP headers:
  • X-Transparency-Context
  • X-Transparency-Protocol
  • X-Transparency-Signature
  • X-Transparency-Inspection
  • X-Transparency-Rejection
  • X-Transparency-Rejection-Reason
  • X-Transparency-Rejection-Policy
  • X-Transparency-Rejection-Details
 References Normative References Key words for use in RFCs to Indicate Requirement Levels Edwards-Curve Digital Signature Algorithm (EdDSA) Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words Informative References AI Risk Management Framework National Institute of Standards and Technology Regulation on Artificial Intelligence European Parliament
ABNF Grammar The following ABNF grammar defines the TRP header format:
Example Records
Minimal Valid Record
Acknowledgments The author would like to thank the AI governance and security communities for their input on this specification.