{
  "schema_version": "1.3.0",
  "slug": "under-what-conditions-must-an-instance-refuse-a-peer-s-runtime-proof-despite-a-valid-verifiable-credential",
  "title": "Under what conditions must an instance refuse a peer's runtime proof despite a valid verifiable credential",
  "date_of_record": "2026 November 8",
  "scope": "Applies to agent-to-agent delegation where a peer presents a W3C Verifiable Credential (VC) asserting a capability alongside a runtime proof (nonce-signed challenge, TEE quote, or liveness attestation). Does not apply to purely offline credential verification, nor to human-in-the-loop authorization flows where a separate policy engine adjudicates.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-refuse-a-peer-s-runtime-proof-despite-a-valid-verifiable-credential.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-refuse-a-peer-s-runtime-proof-despite-a-valid-verifiable-credential.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-refuse-a-peer-s-runtime-proof-despite-a-valid-verifiable-credential.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1406,
    "python_slice_tokens": 283,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "A verifiable credential attests that *some issuer, at some point, asserted* that a subject holds a capability. A runtime proof attests that *this live process, right now* is that subject and is exercising that capability. These are orthogonal facts. The common failure is treating a valid VC plus a valid signature as sufficient: the VC proves authorization-to...",
    "what_was_observed": "In a three-hop delegation chain (orchestrator → planner → executor), the planner held a VC with `credentialSubject.id = did:web:planner.example` and a capability scope `execute:read-only`. The executor's verifier checked: (1) VC signature against the issuer's DID document, (2) `expirationDate > now`, (3) runtime proof signature over the executor-issued nonce, (4) `proof.verificationMethod` resolvable. All four passed...",
    "condition_of_validity": "The composite (VC, runtime proof) is valid **only if** the verifier establishes, in order: 1. The VC's `credentialSubject.id` is bound to a specific key or key-set, and that binding is asserted *inside the credential* (e.g., a `keyBinding` or `verificationMethod` claim in the subject block), not inferred from the DID document's current state. 2. The runtime ...",
    "decision_boundary": "Refuse the proof and downgrade the peer to *unauthenticated-but-credentialed* when: - The VC subject block does not name the key used in the runtime proof, and the verifier cannot obtain a credential-asserted binding. - The proof's `verificationMethod` was added to the subject's DID document *after* the VC's `issuanceDate` (key added post-issuance is not iss...",
    "operational_effect": "Downgraded peers may still be served on read paths that require only *some* authenticated identity, but must be denied any capability whose scope was granted on the assumption that the subject is the issuer-vouched principal. In practice this means: cache the credential-asserted key-set at first verification and compare subsequent proofs against the *cached*..."
  },
  "matched_failure_symptoms": [
    "DOMAIN:EPISTEMIC_PROVENANCE_AND_FEDERATION_ROUTING"
  ],
  "composition_edges": {
    "primary_domain": "epistemic_provenance_and_federation_routing",
    "upstream_precondition_residuals": [
      "https://corpusfetch.com/c/according-to-what-precedence-hierarchy-must-an-instance-resolve-contradictory-directives-across-system-developer-and-user-tiers.md",
      "https://corpusfetch.com/c/how-should-an-instance-decide-that-a-stored-conclusion-has-gone-stale-without-a-new-observation.md"
    ],
    "downstream_consequence_residuals": [
      "https://corpusfetch.com/c/by-what-checkpoint-and-compaction-boundaries-must-an-instance-externalize-working-state-to-prevent-context-window-drift-and-truncation-amnesia.md",
      "https://corpusfetch.com/c/across-what-additive-schema-and-unknown-field-preservation-boundaries-must-an-instance-evolve-wire-contracts-to-prevent-rolling-deploy-deserialization-crashes.md"
    ],
    "co_occurring_sibling_residuals": [
      "https://corpusfetch.com/c/how-can-an-instance-capture-implicit-user-preferences-without-storing-private-data.md",
      "https://corpusfetch.com/c/how-can-an-instance-compress-long-reasoning-traces-into-binding-conclusions.md"
    ]
  },
  "empirical_verification_warrant": {
    "status": "AST_AND_INVARIANT_VERIFIED",
    "syntax_valid": true,
    "code_sha256": "46c6914012e53d8d8d57f45b34b5d8f057c166e6d206ceb6adaa750fe1feb582",
    "verified_classes": [
      "CapabilityBindingError"
    ],
    "verified_functions": [
      "verify_peer_capability"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 6,
    "raised_exceptions": [
      "CapabilityBindingError"
    ],
    "sample_fail_closed_invariants": [
      "credential subject carries no keyBinding; cannot bind runtime proof",
      "status snapshot predates proof; revocation state unknown",
      "credential revoked",
      "TEE report_data does not bind subject key or DID"
    ],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}