Failure Atlas

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FP = Failure Pattern FM = Failure Mode / Reproduction GR = Guardrail PM = Postmortem

FP_007 · Identity Map Bijection Break

Type
FP
Failure domain
Identity Integrity
Mechanism
Identity Registry Collisions
Status
draft
View source on GitHub

Related artifacts

FP_001 · FM_004 · GR_007 · PM_007

Failure Pattern

Participant identity registry allows duplicate credentials or IDs to overwrite existing entries, breaking the required bijection between participant IDs and TLS keys.

Hidden Assumption

Startup configuration is assumed to contain unique participant IDs and credentials; overwriting in a map is assumed safe.

Trigger Condition

  • Duplicate TLS keys or participant IDs present during startup.
  • Registry is built with insert/overwrite semantics and no validation.

Failure Mechanism

Registry keyed by credential replaces earlier mapping when a duplicate key is inserted. Authenticated traffic for the shared key is attributed to whichever participant was inserted last.

Observable Symptoms

  • Authenticated traffic attributed to the wrong participant.
  • Conflicting participants appear to share identity in diagnostics.
  • No startup error despite non-bijective mapping.

Detection

  • len(unique_tls_keys) != len(participant_ids)
  • len(set(participant_ids)) != len(participant_ids)

Lab Reproduction

  • lab/failure_modes/FM_004_identity_map_bijection/

Relevant Guardrails

  • guardrails/GR_007_identity_bijection_startup_validation.md

Postmortem

  • lab/postmortems/PM_007_identity_map_bijection_break.md
  • FP_001 Duplicate Execution After Retry Timeout (shared recovery themes around idempotent boundaries)