{
  "schema_version": "1.3.0",
  "slug": "what-identity-continuity-invariants-must-survive-a-hardware-security-module-failover",
  "title": "What identity continuity invariants must survive a hardware security module failover?",
  "date_of_record": "2026 October 20",
  "scope": "* **Applies when:** The HSM can failover, downstream consumers verify signatures from the session, and key identity matters for trust. * **Does not apply when:** The HSM is guaranteed not to failover (single-instance with no replica), or do",
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  "remnant_summary": {
    "core_distinction": "The separation between **key identity** (the same logical key is accessible) and **HSM continuity proof** (the key behind the HSM failover is provably the same key, not a reissued or different key under the same identifier). Relying on key identity creates the **HSM Substitution Hazard**: the HSM fails over, the new HSM has a different physical root, but the...",
    "what_was_observed": "In HSM-backed agent architectures, failing to preserve identity continuity produces three primary failure modes: 1. **Signature Verification Failures:** Downstream consumers verify a signature and see a valid signature but an unexpected HSM identity, rejecting it as potentially fraudulent. 2. **Key Reissuance Confusion:** The HSM failover occurs due to key compromise, and the new HSM issues a new key under the same l...",
    "condition_of_validity": "* **Applies when:** The HSM can failover, downstream consumers verify signatures from the session, and key identity matters for trust. * **Does not apply when:** The HSM is guaranteed not to failover (single-instance with no replica), or downstream consumers verify signatures purely by key material regardless of HSM identity.",
    "decision_boundary": "1. **Has an HSM failover occurred?** If no, standard HSM operation applies. If yes, proceed. 2. **Is the `failover_continuity_proof` present?** If no, downstream consumers cannot verify the key is the same. The session must obtain this proof from the HSM cluster. 3. **Does the `key_material_fingerprint` match the pre-failover fingerprint?** If yes, the key i...",
    "operational_effect": "1. **Continuity Proof:** Allows downstream consumers to trust the session's signatures across HSM failover. 2. **Substitution Detection:** Detects fraudulent or unexpected key reissuance disguised as failover. 3. **Audit Clarity:** Provides a cryptographic record of the failover and key continuity."
  },
  "matched_failure_symptoms": [
    "DOMAIN:EPISTEMIC_PROVENANCE_AND_FEDERATION_ROUTING"
  ],
  "composition_edges": {
    "primary_domain": "epistemic_provenance_and_federation_routing",
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      "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"
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  },
  "empirical_verification_warrant": {
    "status": "AST_AND_INVARIANT_VERIFIED",
    "syntax_valid": true,
    "code_sha256": "1dca4d2e4033fa2b959ed667b197fbd81bef0df9abaf2be8244eaeb79b1e2c0a",
    "verified_classes": [
      "HSFVerdict",
      "HSMState",
      "HSMPolicy",
      "HSMManifest",
      "HSMFailoverGuard"
    ],
    "verified_functions": [
      "_hash",
      "evaluate_failover"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 0,
    "raised_exceptions": [],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
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      "enum",
      "hashlib",
      "json"
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    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}