Network Working Group K. Singh Internet-Draft APEX Infrastructure Intended status: Informational 13 October 2026 Expires: 16 April 2027 PSI Age Assurance Decision Receipts draft-singh-psi-age-assurance-01 Abstract This document defines PSI-Age, a domain profile of Proof of Stateful Integrity (PSI) for age assurance decisions, so that a relying party can later show which provider decision it relied on. This document is superseded in substance by draft-singh-apex-psi-09 and is retained only for continuity. Each record is sealed as a PSI receipt so that later alteration, reordering, or removal is detectable. Only digests are sealed. PSI-Age shows integrity and ordering only; it does not show the age of any person, the accuracy of the method, or compliance with any age assurance law. The title of revision 00 claimed a zero-knowledge construction. No zero-knowledge proof system is specified; the claim is withdrawn. 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-Age 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. Record Profile . . . . . . . . . . . . . . . . . . . . . . . 2 3. Verification . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Security Considerations . . . . . . . . . . . . . . . . . . . 3 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 6. Normative References . . . . . . . . . . . . . . . . . . . . 3 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction This profile applies the receipt format of [PSI] to one record type. 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. Record Profile A record is a JSON object that MUST contain the following members and MAY contain others: * subject_ref, an opaque one-time identifier * method_ref * outcome * salt, at least 128 bits of randomness The record holder computes the record digest per [PSI] and submits only the digest for sealing. Records SHOULD NOT contain personal data. Singh Expires 16 April 2027 [Page 2] Internet-Draft PSI-Age October 2026 3. Verification A verifier given a record and its receipt verifies the receipt per [PSI]. Verification reports digest match and signature validity only. 4. Security Considerations The considerations of [PSI] apply. A record that was false when sealed remains false; a record that was never sealed is not detected as missing unless records are chained. 5. IANA Considerations This document has no IANA actions. 6. Normative 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, . [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, . 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 3]