Web4 Assessment Assertions

Abstract

This document defines an implementation-neutral envelope for externally presented assessment results, including subject, issuer, policy, result, validity, evidence commitments, proof, and current status, while protected methods remain confidential.¶

1. Conventions and Terminology

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.¶

2. Introduction

This document defines an implementation-neutral envelope for an externally presented assessment result. It standardizes the verification surface, not the method used to calculate the result.¶

A Conforming Evaluator MAY use a public, proprietary, confidential, automated, human-mediated, cryptographic, mathematical, geometric, statistical, or machine-learning method. KCoordinate and KQAS are possible implementations but are neither required nor specified here.¶

3. Scope and Non-Goals

This document defines assertion syntax, issuer accountability, policy context, temporal validity, evidence commitments, proof carriage, and status resolution. It does not define coordinate spaces, transforms, metrics, mappings, derivations, score equations, weights, thresholds, calibration, features, training inputs, or private evidence.¶

4. Assessment Assertion

An Assessment Assertion MUST identify the assertion, subject, accountable issuer, applicable policy or profile, outcome, issuance time, temporal validity, proof mechanism, and current-status mechanism. A profile MAY require an assurance-class reference and evidence commitments.¶

{
  "assertion_id": "urn:web4:assertion:01JEXAMPLE",
  "assertion_type": "assessment",
  "subject_id": "did:example:node-842",
  "issuer_id": "did:example:evaluator-1",
  "policy_id": "urn:web4:policy:admission:v1",
  "outcome": "conformant",
  "issued_at": "2026-09-12T13:59:00Z",
  "valid_until": "2026-12-12T13:59:00Z",
  "status_uri": "https://status.example/assertions/01JEXAMPLE",
  "proof": {
    "type": "ExampleProof",
    "verification_method": "did:example:evaluator-1#key-1",
    "value": "BASE64URL-SIGNATURE"
  }
}

5. Evaluator Requirements

A Conforming Evaluator MUST expose sufficient information to verify issuer, subject, policy context, temporal validity, integrity protection, and current status. It MUST retain records required by policy and support correction, supersession, suspension, expiration, or revocation where applicable.¶

Conformance MUST NOT require disclosure of protected inputs, coordinate representations, model parameters, inference processes, private evidence, calibration material, scoring functions, or trade-secret methods.¶

6. Verifier Requirements

A Verifier MUST validate issuer authority, subject binding, policy identity and version, temporal validity, proof integrity, and current status before treating an assertion as active. Unresolved status MUST be treated as indeterminate.¶

7. Status Model

The base status vocabulary is active, suspended, superseded, revoked, expired, and indeterminate.¶

8. Conformance

Conformance does not establish that an assessment conclusion is true or that its subject is secure, lawful, or suitable for a particular purpose.¶

9. Relationship to Research Artifacts

Broader Web4 architectural work is described informatively in [I-D.reilly-web4]. Informative research materials MAY be published as versioned scholarly artifacts, including DOI-addressable records.¶

A research artifact is not required for conformance unless expressly incorporated as a Normative Reference by a named profile. Referencing or verifying an artifact does not establish the truth of its conclusions, regulatory approval, certification, security, legal compliance, or IETF endorsement.¶

A Conforming Implementation MUST NOT require access to KCoordinate, KQAS, or another protected internal assessment method unless a separate deployment agreement selects that implementation.¶

10. Security Considerations

Implementations MUST authenticate issuers, validate proof integrity, check proof purpose, enforce temporal validity, and resolve current status before relying on an object.¶

Implementations MUST address identifier confusion, issuer impersonation, key compromise, algorithm downgrade, replay, stale status, unauthorized supersession, cross-policy confusion, canonicalization ambiguity, denial of service, and fail-open handling of indeterminate validity.¶

Evidence commitments can confirm correspondence with committed bytes but do not prove truth, completeness, legality, provenance, or fitness for purpose. Profiles SHOULD define privacy-preserving commitment procedures for low-entropy artifacts.¶

11. Privacy Considerations

Persistent identifiers, status queries, proofs, policy references, and linked receipts can enable correlation. Implementations MUST minimize disclosed data and SHOULD use unlinkable or pairwise identifiers where they satisfy policy.¶

Private evidence MAY remain undisclosed and be represented by a cryptographic commitment. Retention and erasure requirements MUST be specified by policy and account for applicable obligations.¶

12. IANA Considerations

This document requests no IANA actions.¶

13. 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, <https://www.rfc-editor.org/info/rfc2119>.

[RFC8174]

Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, <https://www.rfc-editor.org/info/rfc8174>.

14. Informative References

[I-D.reilly-web4]

Reilly, L. J., "Web4: A Verifiable, Agent-Native Architecture for the World Wide Web", Work in Progress, Internet-Draft, draft-reilly-web4-00, 26 August 2026, <https://datatracker.ietf.org/doc/draft-reilly-web4/>.