Network Working Group K. Singh Internet-Draft APEX Infrastructure Intended status: Informational 13 October 2026 Expires: 16 April 2027 The Compliance-Receipt HTTP Response Header Field draft-singh-psi-http-00 Abstract This document defines the Compliance-Receipt HTTP response header field, a Structured Field that carries a reference to a Proof of Stateful Integrity (PSI) receipt for the response. The signature covers every security-relevant parameter. The header shows that the issuer sealed a digest of the response; despite its name it does not show that the response, or the service, complies with any law or policy. 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 16 April 2027. Copyright Notice Copyright (c) 2026 IETF Trust and the persons identified as the document authors. All rights reserved. Singh Expires 16 April 2027 [Page 1] Internet-Draft PSI HTTP October 2026 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 . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Header Field Definition . . . . . . . . . . . . . . . . . . . 2 3. Signature Input . . . . . . . . . . . . . . . . . . . . . . . 3 4. Verification . . . . . . . . . . . . . . . . . . . . . . . . 3 5. Security Considerations . . . . . . . . . . . . . . . . . . . 3 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 3 7.1. Normative References . . . . . . . . . . . . . . . . . . 3 7.2. Informative References . . . . . . . . . . . . . . . . . 4 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction Clients that receive machine-generated responses may want a durable, independently checkable record that a given response was issued. The key words "MUST", "MUST NOT", "SHOULD", and "MAY" 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. 2. Header Field Definition Compliance-Receipt is a Dictionary Structured Field [RFC9651]. Members: * v: Integer, version; this document defines 1. * rid: String, receipt identifier. * h: Byte Sequence, SHA-256 of the response content. * st: Token, one of sealed or pending. * kid: String, signing key identifier. * sig: Byte Sequence, Ed25519 signature. Singh Expires 16 April 2027 [Page 2] Internet-Draft PSI HTTP October 2026 All members except sig are REQUIRED. Unknown members MUST be ignored. A field that fails to parse, repeats a member, or lacks a required member MUST be treated as absent. Compliance-Receipt: v=1, rid="APEX-NTR-1EEBEA8EE8EBF44A", h=::, st=sealed, kid="apex-psi-2026", sig=:: 3. Signature Input The signature input is the serialization, per Section 4.1 of [RFC9651], of the Dictionary containing all members other than sig, in the order v, rid, h, st, kid. Signing only rid would allow status or digest substitution and is not permitted. The signature is Ed25519 [RFC8032]; keys are discovered from /.well-known/compliance- receipt on the issuer origin. 4. Verification A client recomputes SHA-256 of the received content, compares it with h, reconstructs the signature input, and verifies sig. It MAY then resolve rid to the full receipt. Status pending MUST NOT be presented as anchored. 5. Security Considerations The header is set by the server; an intermediary able to rewrite responses can strip it. It binds content, not the identity of the requester. Content encodings change bytes; h is over the content as received after removing transfer codings but before content decoding. 6. IANA Considerations This document has no IANA actions in this revision. Registration in the Hypertext Transfer Protocol Field Name Registry will be requested only if this document advances. 7. References 7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, May 2017, . Singh Expires 16 April 2027 [Page 3] Internet-Draft PSI HTTP October 2026 [RFC9651] Nottingham, M. and P-H. Kamp, "Structured Field Values for HTTP", RFC 9651, September 2024, . [RFC8032] Josefsson, S. and I. Liusvaara, "Edwards-Curve Digital Signature Algorithm (EdDSA)", RFC 8032, January 2017, . 7.2. Informative References [PSI] Singh, K., "Proof of Stateful Integrity (PSI): Signed, Merkle-Committed Receipts for Digital Records", Work in Progress, Internet-Draft, draft-singh-psi-02, October 2026, . Author's Address Kawaljeet Singh APEX Infrastructure Melbourne Victoria Australia Email: kawaljeet.singh3008@gmail.com URI: https://ai-governance-standard.com Singh Expires 16 April 2027 [Page 4]