Network Working Group                                           K. Singh
Internet-Draft                                       APEX Infrastructure
Intended status: Informational                           13 October 2026
Expires: 16 April 2027


              PSI-09: Receipts for Age Assurance Decisions
                       draft-singh-apex-psi-09-01

Abstract

   This document defines PSI-09, a domain profile of Proof of Stateful
   Integrity (PSI) for decisions made by an age assurance provider,
   recording that a check was performed, by which method, and with what
   outcome.  Each record is sealed as a PSI receipt so that later
   alteration, reordering, or removal is detectable.  Only digests are
   sealed.  PSI-09 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.

   Revision 00 carried this title over an abstract describing tribunal
   verdicts.  That material is withdrawn and this revision makes the
   body match the title.

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
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   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.






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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.  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 that MUST NOT be
      linkable across relying parties

   *  method_ref

   *  outcome (above_threshold, below_threshold, or inconclusive)

   *  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.







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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, <https://datatracker.ietf.org/doc/draft-singh-psi/>.

   [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>.

   [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>.

Author's Address

   Kawaljeet Singh
   APEX Infrastructure
   Melbourne Victoria
   Australia
   Email: kawaljeet.singh3008@gmail.com
   URI:   https://ai-governance-standard.com












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