{
  "schema_version": "1.3.0",
  "slug": "how-does-an-instance-detect-a-compromised-federation-trust-anchor-when-the-did-document-is-served-from-a-resolver-the-verifier-itself-controls",
  "title": "How does an instance detect a compromised federation trust anchor when the DID document is served from a resolver the verifier itself controls",
  "date_of_record": "2026 November 11",
  "scope": "Applies to cross-org agent federation where an agent instance validates a peer's DID document (and its `verificationMethod` / `service` entries) against a trust anchor that is itself discovered via a DID resolution path controlled by the *verifying* organization. Does not apply to pure peer-to-peer DID exchange with out-of-band anchor pinning, nor to resolution paths where the anchor DID is resolved by an independent, mutually-distrusted resolver.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/how-does-an-instance-detect-a-compromised-federation-trust-anchor-when-the-did-document-is-served-from-a-resolver-the-verifier-itself-controls.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/how-does-an-instance-detect-a-compromised-federation-trust-anchor-when-the-did-document-is-served-from-a-resolver-the-verifier-itself-controls.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/how-does-an-instance-detect-a-compromised-federation-trust-anchor-when-the-did-document-is-served-from-a-resolver-the-verifier-itself-controls.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1602,
    "python_slice_tokens": 263,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The boundary is between **anchor authenticity** (the DID document genuinely belongs to the org that owns the DID) and **anchor freshness/consistency** (the document the verifier is looking at is the one the anchor owner currently publishes, not a stale, rolled-back, or substituted copy). Most federation implementations check authenticity — signature over the...",
    "what_was_observed": "In a federation between two orgs (call them A and B), A's agent gateway resolved B's trust-anchor DID through A's own internal DID resolver (a caching proxy in front of a public ledger). B rotated its anchor signing key after a suspected key compromise, publishing a new DID document with the old key revoked and a `deactivated`-free but rotated `verificationMethod`. B's agents began signing federation assertions with ...",
    "condition_of_validity": "The invariant holds only when the verifier can establish, for the anchor document it is about to trust, at least one of: 1. **Monotonic version evidence** — the document carries a `versionId` / sequence number / ledger timestamp that the verifier has previously observed and can compare against (`new >= last_seen`). Rollback is then detectable locally. 2. **I...",
    "decision_boundary": "An instance must refuse to elevate a peer to federated-trust status when it cannot distinguish a fresh anchor document from a stale one. Concretely, the decision boundary is: - If `versionId` is present and `versionId >= last_seen_versionId` for this anchor → accept, update `last_seen`. - If `versionId` is absent but ≥2 independent resolvers agree and the co...",
    "operational_effect": "After the incident, A's gateway was changed so that (a) the resolver's fallback-to-stale path was removed for verification reads and retained only for liveness probes, (b) every anchor document carries a `versionId` that the verifier persists per-(org, DID), and (c) a regression or single-source-only resolution raises a hard error that halts federation onboa..."
  },
  "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": "c0cf6ba06751458b562e44c3ddc9f2449ab8b8a186529f3db6ede546544318f5",
    "verified_classes": [
      "AnchorFreshnessError",
      "AnchorObservation",
      "AnchorState",
      "FederationVerifier"
    ],
    "verified_functions": [
      "__init__",
      "validate_anchor"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 4,
    "raised_exceptions": [
      "AnchorFreshnessError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "time",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}