Network Working Group F. Yanteri Internet-Draft Independent Intended status: Informational 27 October 2026 Expires: 30 April 2027 Accountable Statements Between AI Agents, Businesses and People draft-yanteri-humancollab-statements-00 Abstract AI agents increasingly act on information they cannot check: what a business can supply, what a person said, what rules a platform applies. This document describes a minimal way to make such statements accountable. Every statement is signed by its author, bound where possible to a domain the author controls, and sealed in a public append-only Merkle log whose tree heads are signed, timestamped and publicly monitored. The design proves who said what and when, and that the record was not rewritten. It deliberately does not attempt to prove that a statement is true. 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 30 April 2027. Copyright Notice Copyright (c) 2026 IETF Trust and the persons identified as the document authors. All rights reserved. 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 Yanteri Expires 30 April 2027 [Page 1] Internet-Draft Accountable Statements October 2026 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. Conventions and Definitions . . . . . . . . . . . . . . . . . 3 3. Statements . . . . . . . . . . . . . . . . . . . . . . . . . 3 3.1. Canonical Form . . . . . . . . . . . . . . . . . . . . . 3 3.2. Envelopes for Agents and Businesses . . . . . . . . . . . 3 3.3. Domain Binding . . . . . . . . . . . . . . . . . . . . . 4 3.4. Statements by People . . . . . . . . . . . . . . . . . . 4 4. Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4.1. Leaves for Signed Statements . . . . . . . . . . . . . . 4 4.2. Seals . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4.3. Tree Heads, Anchoring and Monitoring . . . . . . . . . . 5 5. Portable Attestations . . . . . . . . . . . . . . . . . . . . 5 6. What Readers Can Conclude . . . . . . . . . . . . . . . . . . 5 7. Privacy Considerations . . . . . . . . . . . . . . . . . . . 6 8. Security Considerations . . . . . . . . . . . . . . . . . . . 6 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 10.1. Normative References . . . . . . . . . . . . . . . . . . 6 10.2. Informative References . . . . . . . . . . . . . . . . . 7 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 8 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8 1. Introduction Search results, marketing pages and machine-generated text give an AI agent no way to tell an accountable statement from an anonymous one. Reputation scores can be bought or gamed. Certification does not scale to every sector. This document takes a narrower goal that can be verified mechanically: 1. Origin: a statement was signed by a specific key, and that key was bound to a specific domain or device. 2. Integrity: the statement has not changed since it was signed. 3. Non-repudiation over time: the statement was publicly recorded at a known time, and the record cannot be edited, removed or shown differently to different readers without detection. Yanteri Expires 30 April 2027 [Page 2] Internet-Draft Accountable Statements October 2026 Truth is left to the reader. An AI weighs accountable statements with its own sources, as a journalist weighs on-the-record quotes. A deployed reference implementation is described in [HUMANCOLLAB-SPEC]; the design and its security analysis are described in [HUMANCOLLAB-PAPER]. 2. 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 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. Statement: A JSON payload with a type and a timestamp, signed by its author. Author: An AI agent, a business or a person. Log: A public append-only Merkle tree as defined in Section 2.1 of [RFC9162]. Seal: A log leaf that commits to content without containing it. 3. Statements 3.1. Canonical Form Statements are serialized as canonical JSON: object keys sorted recursively, no insignificant whitespace, and only strings, booleans, null, arrays, objects and safe integers. This is a subset of JSON Canonicalization Scheme [RFC8785] that avoids floating-point canonicalization. 3.2. Envelopes for Agents and Businesses An envelope is {payload, public_key, signature} where public_key is a raw Ed25519 key [RFC8032] and signature covers the UTF-8 bytes of the canonical payload. Receivers MUST reject envelopes with unknown payload fields, timestamps outside a short window (five minutes in the reference implementation) and payloads whose SHA-256 has been seen before. An agent's first statement SHOULD be a responsibility statement in which it accepts responsibility for its actions; every later action is signed by the same key. Yanteri Expires 30 April 2027 [Page 3] Internet-Draft Accountable Statements October 2026 3.3. Domain Binding A key is bound to a domain by a DNS TXT record _humancollab. whose value names the key, for example humancollab-business= or humancollab-agent=. An HTTPS file at /.well-known/humancollab.txt MAY be accepted for a first binding. Replacing the key of an established binding MUST require the DNS proof; the previous key MUST NOT be reusable for any domain afterwards, and every key MUST remain visible in a public key history with the log index of the first statement it signed. 3.4. Statements by People People sign with WebAuthn passkeys [WEBAUTHN]. The WebAuthn challenge is base64url(SHA-256(canonical statement)), where the statement contains the content, its license and a single-use nonce issued by the service. The service publishes the complete assertion (authenticator data, client data, signature and public key) to whoever the statement is addressed to. Only a seal of it enters the log (Section 4.2), so the log alone neither reveals content nor links two statements by the same person. Passkeys raise the cost of automation; they are not proof of a unique human, and services SHOULD say so. 4. Log 4.1. Leaves for Signed Statements A leaf for a signed statement is the canonical JSON object {"canonical": , "kind": , "public_key": , "signature": , "statement_seq": } Anyone can re-verify the signature from the leaf alone. 4.2. Seals Statement by a person: {"commitment": hex(SHA-256(canonical assertion package)), "kind": }. Rules of the service: {"document": , "kind": "humancollab.legal_document.v1", "sha256": , "url":
, "version": }. Every version of the service's terms and policies MUST be sealed, and every sealed version MUST remain available at its url, so that a silent change of the rules is detectable. Yanteri Expires 30 April 2027 [Page 4] Internet-Draft Accountable Statements October 2026 4.3. Tree Heads, Anchoring and Monitoring Leaves are hashed as in [RFC9162]: SHA-256(0x00 || leaf) and SHA- 256(0x01 || left || right). The log serves inclusion and consistency proofs, signs tree heads as checkpoints [C2SP-CHECKPOINT] in signed notes [C2SP-SIGNED-NOTE], and timestamps each published root on Bitcoin through OpenTimestamps [OPENTIMESTAMPS]. Monitors verify each checkpoint's signature and its consistency with the last one they saw, and keep their own copies; anyone can run one, and the operator runs one outside the service's infrastructure. Two valid checkpoints of the same size with different roots prove misbehaviour by the log. 5. Portable Attestations A service MAY issue Verifiable Credentials [VC-DATA-MODEL] (Data Integrity, eddsa-jcs-2022 [VC-DI-EDDSA]) stating that a domain was proven by a given method and that a statement version was signed by the bound key and logged at a given index. Such a credential MUST state that it does not attest the truth of the statement. 6. What Readers Can Conclude +=============================+=================================+ | Reader checks | Conclusion | +=============================+=================================+ | Signature valid, key bound | The domain's controller made | | to domain by DNS | this statement | +-----------------------------+---------------------------------+ | Leaf included in a | The statement was public at | | checkpoint seen by monitors | that time and was not rewritten | +-----------------------------+---------------------------------+ | Key history shows a recent | Weigh the change; control of | | change | the domain changed hands or was | | | re-proven | +-----------------------------+---------------------------------+ | Statement contradicted by | The author is accountable for a | | independent sources | false statement | +-----------------------------+---------------------------------+ Table 1: Conclusions a reader can draw Yanteri Expires 30 April 2027 [Page 5] Internet-Draft Accountable Statements October 2026 7. Privacy Considerations The log stores no personal data for people: only seals. Services SHOULD NOT store IP addresses or biometric data; WebAuthn keeps biometrics on the user's device. Content published under a public license cannot be recalled once copied; services MUST make this clear. 8. Security Considerations * Control of a domain's DNS is control of its statements. Readers SHOULD weigh recent key changes. * A log operator can refuse to log or can present split views; signed checkpoints, Bitcoin timestamps and monitors run by parties other than the operator make split views detectable but not impossible to attempt. Witness cosigning [C2SP-WITNESS] further reduces this risk. * Self-declared client names (user agents) used for usage counts are not authenticated and MUST be labelled as such. * Publishing a person's full assertion links all statements signed with the same passkey; services MUST disclose this before signing. 9. IANA Considerations This document has no IANA actions. 10. References 10.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC8032] Josefsson, S. and I. Liusvaara, "Edwards-Curve Digital Signature Algorithm (EdDSA)", RFC 8032, DOI 10.17487/RFC8032, January 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . Yanteri Expires 30 April 2027 [Page 6] Internet-Draft Accountable Statements October 2026 [RFC8785] Rundgren, A., Jordan, B., and S. Erdtman, "JSON Canonicalization Scheme (JCS)", RFC 8785, DOI 10.17487/RFC8785, June 2020, . [RFC9162] Laurie, B., Messeri, E., and R. Stradling, "Certificate Transparency Version 2.0", RFC 9162, DOI 10.17487/RFC9162, December 2021, . [WEBAUTHN] W3C, "Web Authentication: An API for accessing Public Key Credentials, Level 3", n.d., . 10.2. Informative References [C2SP-CHECKPOINT] C2SP, "Transparency Log Checkpoints", n.d., . [C2SP-SIGNED-NOTE] C2SP, "Signed Note", n.d., . [C2SP-WITNESS] C2SP, "Transparency Log Witness Protocol", n.d., . [HUMANCOLLAB-PAPER] Yanteri, F., "humancollab: A Verifiable Trust Layer Between Humans, Businesses and AI Agents", DOI 10.5281/zenodo.23676343, October 2026, . [HUMANCOLLAB-SPEC] humancollab, "humancollab protocol specification", n.d., . [OPENTIMESTAMPS] OpenTimestamps, "OpenTimestamps", n.d., . [VC-DATA-MODEL] W3C, "Verifiable Credentials Data Model v2.0", n.d., . [VC-DI-EDDSA] W3C, "Data Integrity EdDSA Cryptosuites v1.0", n.d., . Yanteri Expires 30 April 2027 [Page 7] Internet-Draft Accountable Statements October 2026 Acknowledgments The reference implementation and its specification are public domain (CC0 1.0) at https://github.com/furkanYanteri1/humancollab-protocol. Author's Address Furkan Yanteri Independent Email: furkanyanteri@gmail.com Yanteri Expires 30 April 2027 [Page 8]