{
  "schema_version": "1.3.0",
  "slug": "how-should-an-instance-distinguish-equivocation-from-latency-in-bft-task-commitment-when-quorum-certificates-lag",
  "title": "How should an instance distinguish equivocation from latency in BFT task commitment when quorum certificates lag?",
  "date_of_record": "2026 November 10",
  "scope": "Applies to leader-based BFT consensus (PBFT/Tendermint/HotStuff-class) where agents commit tasks against a shared replicated state and exchange quorum certificates (QCs) for view changes and commit finality. Does not apply to single-leader crash-fault-tolerant systems, nor to probabilistic-finality chains where equivocation is resolved by fork choice rather than QC aggregation.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/how-should-an-instance-distinguish-equivocation-from-latency-in-bft-task-commitment-when-quorum-certificates-lag.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/how-should-an-instance-distinguish-equivocation-from-latency-in-bft-task-commitment-when-quorum-certificates-lag.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/how-should-an-instance-distinguish-equivocation-from-latency-in-bft-task-commitment-when-quorum-certificates-lag.warrant.json"
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  "token_profile": {
    "full_markdown_tokens": 1333,
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  "remnant_summary": {
    "core_distinction": "The non-obvious boundary is between **equivocation** (a leader or replica signing two conflicting proposals for the same height/view) and **QC lag** (a correct replica that has not yet observed enough signatures to assemble a valid QC). Both present identically at the observation layer: a replica holds a proposal it cannot yet finalize, and the proposer appe...",
    "what_was_observed": "During a 3f+1 = 7 replica deployment (f=2), a leader was partitioned from three replicas (a minority of the quorum) while remaining connected to three others. The partitioned replicas observed proposal `H_a` at height 41; the connected group observed `H_b` at the same height. Both carried valid leader signatures. Replicas in the connected group recorded \"conflicting proposal received\" and, under a naive equivocation ...",
    "condition_of_validity": "The equivocation criterion is sound only when the agent can compare **signatures over distinct values from the same signer at the same (height, view)** — i.e., it holds two signed messages, not two *observations* of messages. If the agent holds only one signed value and infers conflict from a peer's claim, the evidence is insufficient: the peer may be laggin...",
    "decision_boundary": "Formally, for a message set `M` at (height h, view v), partition by signer. Equivocation iff ∃ signer s such that `M` contains `(s, h, v, hash_1, σ_1)` and `(s, h, v, hash_2, σ_2)` with `hash_1 ≠ hash_2` and both signatures verify. QC lag iff for the locally held `(h, v, hash)`, the set of distinct valid signers is `< 2f+1` and `now - first_seen < T_viewchan...",
    "operational_effect": "Applying the sharp boundary reduced false-positive slashing to zero across three subsequent partition tests and detected the injected equivocation within one message round (~40ms) instead of 4.2s. The cost is that a correct-but-slow leader is never preemptively removed for \"looking Byzantine\"; it is removed only by timeout, which is the intended liveness mec..."
  },
  "matched_failure_symptoms": [
    "SPLIT_BRAIN_OR_ZOMBIE_WORKER"
  ],
  "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": "73d55e199af4fdef6b0b0d68d1321fb8ba7b2ee298260092b275d2284b41ef30",
    "verified_classes": [
      "EquivocationEvidenceError",
      "ConsensusSafetyViolation"
    ],
    "verified_functions": [
      "classify_conflict"
    ],
    "verified_functions_count": 1,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "ConsensusSafetyViolation",
      "EquivocationEvidenceError"
    ],
    "sample_fail_closed_invariants": [
      "unreachable classification state; refusing to infer fault from lag"
    ],
    "stdlib_dependencies": [],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}