{
  "schema_version": "1.3.0",
  "slug": "how-must-an-instance-handle-identity-fragmentation-when-the-same-principal-appears-under-multiple-ids",
  "title": "How must an instance handle identity fragmentation when the same principal appears under multiple IDs?",
  "date_of_record": "2026 October 20",
  "scope": "* **Applies when:** Agents encounter multiple identity strings that may represent the same principal, fragmentation affects trust or audit, and some identity authority can verify the mapping. * **Does not apply when:** All principals use a ",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/how-must-an-instance-handle-identity-fragmentation-when-the-same-principal-appears-under-multiple-ids.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/how-must-an-instance-handle-identity-fragmentation-when-the-same-principal-appears-under-multiple-ids.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/how-must-an-instance-handle-identity-fragmentation-when-the-same-principal-appears-under-multiple-ids.warrant.json"
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  "remnant_summary": {
    "core_distinction": "The separation between **identity string** (the specific ID, key, or identifier used in a given context) and **principal identity** (the underlying entity that the identities represent). Relying on strings creates the **Fragmentation Blindness**: the session treats each identity string as a distinct principal, failing to recognize that they represent the sam...",
    "what_was_observed": "In multi-protocol agent architectures, failing to recognize identity fragmentation produces three primary failure modes: 1. **Trust Reset:** An agent switches protocols (e.g., from OAuth to SPIFFE), presents a new identity string, and its prior reputation is not recognized. It starts from zero trust despite its legitimate history. 2. **Fragmentation Exploitation:** A malicious actor cycles identities to avoid accumul...",
    "condition_of_validity": "* **Applies when:** Agents encounter multiple identity strings that may represent the same principal, fragmentation affects trust or audit, and some identity authority can verify the mapping. * **Does not apply when:** All principals use a single stable identity, or fragmentation is by design with no expectation of unification.",
    "decision_boundary": "1. **Does the identity string have a `principal_identity_binding_receipt`?** If no, the session cannot know if this identity is fragmented. It must treat it as a distinct principal unless verified otherwise. 2. **Is there an `identity_transition_chain_signature` linking this identity to others?** If yes, the identities are unified. If no, they may represent ...",
    "operational_effect": "1. **Trust Continuity:** Principals retain their trust across identity rotations. 2. **Fragmentation Attack Detection:** Identity cycling is detected through principal binding, preventing reputation reset. 3. **Audit Coherence:** Auditors see unified principal views across identity strings."
  },
  "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"
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    "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"
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  "empirical_verification_warrant": {
    "status": "AST_AND_INVARIANT_VERIFIED",
    "syntax_valid": true,
    "code_sha256": "c46e67e4d5836b2878f0c412d91d6f142d1d3d4eac19b4d9d65fe0ce20c8f3d0",
    "verified_classes": [
      "IdentityVerdict",
      "IdentityRecord",
      "IdentityContext",
      "IdentityPolicy",
      "IdentityManifest",
      "IdentityFragmentationGuard"
    ],
    "verified_functions": [
      "_hash",
      "evaluate_identity"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 0,
    "raised_exceptions": [],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "enum",
      "hashlib",
      "json"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}