{
  "schema_version": "1.3.0",
  "slug": "under-what-conditions-must-an-instance-re-attest-its-agent-identity-after-a-hardware-key-rotation-versus-treat-the-rotation-as-a-transparent-continuit",
  "title": "Under what conditions must an instance re-attest its agent identity after a hardware key rotation versus treat the rotation as a transparent continuity event",
  "date_of_record": "2026 November 14",
  "scope": "Applies to runtime agents whose workload identity is bound to a hardware-backed key (TPM 2.0 EK/AK, SEV-SNP VCEK-derived key, or secure-enclave-resident signing key) and whose authorization decisions depend on continuous posture verification. Does not apply to soft-key identities, nor to key rotations performed as part of a planned, quiesced maintenance window where the control plane has already invalidated all prior attestation tokens.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-re-attest-its-agent-identity-after-a-hardware-key-rotation-versus-treat-the-rotation-as-a-transparent-continuit.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-re-attest-its-agent-identity-after-a-hardware-key-rotation-versus-treat-the-rotation-as-a-transparent-continuit.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/under-what-conditions-must-an-instance-re-attest-its-agent-identity-after-a-hardware-key-rotation-versus-treat-the-rotation-as-a-transparent-continuit.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1580,
    "python_slice_tokens": 288,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "A hardware key rotation has two plausible interpretations inside a running agent, and conflating them is the boundary failure: 1. **Transparent continuity** — the *identity* (the logical agent principal) is unchanged; only the *proof carrier* (the signing key) changed. The platform attests that the new key belongs to the same measured boot chain and the same...",
    "what_was_observed": "In a fleet running SEV-SNP guests with continuous posture verification, a rolling kernel update triggered SNP guest key re-derivation on ~4% of instances. The control plane's rotation handler classified every key change as a continuity event: it rebound the existing attestation token to the new VCEK and extended the token's TTL. The agents continued to emit posture heartbeats signed by the new key. The failure surfac...",
    "condition_of_validity": "Treat a hardware key rotation as transparent continuity **if and only if all of the following hold**: - The new key's attestation report chains to the same root of trust (same EK certificate chain, same AMD cert ARK/ASK, same endorsement hierarchy) as the key it replaces. - The `measurement` (and, where present, `host_data`, `report_data` binding to the prin...",
    "decision_boundary": "The boundary is drawn on **measurement equivalence, not key equivalence**. A useful operational test: - If you can answer \"the new key attests the same measured state as the old key\" from data you collected *at rotation time*, it is continuity. - If you are inferring equivalence from \"the principal ID is the same\" or \"the rotation was scheduled,\" you are gue...",
    "operational_effect": "Misclassifying a re-attestation event as continuity produces a *silent* authorization drift: policy engines keep approving a workload whose measured state they no longer actually know. The failure is silent because every cryptographic check passes — signatures are valid, keys are hardware-backed, heartbeats arrive on time. The only broken link is the semanti..."
  },
  "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": "5a939e1d47dc6a7d222067183e6994835fb7712314e3868ec79d28352fa6f2e6",
    "verified_classes": [
      "AttestationRotationError",
      "AttestationReport",
      "ActiveToken"
    ],
    "verified_functions": [
      "classify_rotation",
      "apply_rotation"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 3,
    "raised_exceptions": [
      "AttestationRotationError"
    ],
    "sample_fail_closed_invariants": [
      "rotation requires full re-attestation: measurement or root of trust changed; old token must not be extended"
    ],
    "stdlib_dependencies": [
      "dataclasses",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}