<?xml version="1.0" encoding="UTF-8"?>
<reference anchor="I-D.vso-cpp-core" target="https://datatracker.ietf.org/doc/html/draft-vso-cpp-core-03">
   <front>
      <title>Content Provenance Profile (CPP) Core</title>
      <author initials="K." surname="Tokachi" fullname="TOKACHI KAMIMURA">
         <organization>VeritasChain Co., Ltd.</organization>
      </author>
      <date month="August" day="2" year="2026" />
      <abstract>
	 <t>   The Content Provenance Profile (CPP) is an open specification for
   cryptographically verifiable media capture provenance.  This document
   defines the core data model, hashing conventions, Merkle tree
   construction rules, RFC 3161 Time-Stamp Authority (TSA) anchoring
   protocol, and offline verification procedures for CPP.

   CPP enables capture devices to produce tamper-evident provenance
   records that bind media content to external timestamps via trusted
   third parties.  Unlike self-attestation models, CPP requires
   independent timestamp verification through RFC 3161 TSA services,
   providing externally verifiable proof of when media was captured.

   CPP defines self-attested signer identity, hardware-backed key
   requirements, chain context for partial submission detection, a
   Completeness Invariant for omission detection, an OPTIONAL depth
   analysis extension for screen detection, and an OPTIONAL Pre-Publish
   Verification Extension.  It also defines interoperability mappings
   with the C2PA specification.

   This revision (-03) corrects a normative length constraint on the
   LeafHashMethod value, corrects the description of the relationship
   between the CPP Merkle construction and Certificate Transparency,
   adds a verifier obligation to cross-check TreeSize against the sealed
   event count, documents the limits of leaf-duplication padding, and
   positions CPP within the Verifiable AI Provenance Framework (VAP)
   profile family and relative to the SCITT architecture (RFC 9943).

	 </t>
      </abstract>
   </front>
   <seriesInfo name="Internet-Draft" value="draft-vso-cpp-core-03" />
   
</reference>
