{
  "schema_version": "1.3.0",
  "slug": "how-should-an-instance-distinguish-coalition-quorum-equivocation-from-benign-view-change-overlap-in-bft-agent-consensus",
  "title": "How should an instance distinguish coalition quorum equivocation from benign view-change overlap in BFT agent consensus",
  "date_of_record": "2026 November 13",
  "scope": "Applies to Byzantine fault-tolerant coalition protocols where agents sign votes per view and a quorum certificate (QC) is formed by 2f+1 matching votes over n=3f+1 members. Does not apply to crash-fault-only consensus, to leaderless DAG-based structures without view numbers, or to protocols that enforce a strict non-overlapping view boundary by wall-clock synchronization.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/how-should-an-instance-distinguish-coalition-quorum-equivocation-from-benign-view-change-overlap-in-bft-agent-consensus.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/how-should-an-instance-distinguish-coalition-quorum-equivocation-from-benign-view-change-overlap-in-bft-agent-consensus.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/how-should-an-instance-distinguish-coalition-quorum-equivocation-from-benign-view-change-overlap-in-bft-agent-consensus.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 1177,
    "python_slice_tokens": 226,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The non-obvious boundary is between **quorum equivocation** (a Byzantine agent signing two conflicting votes in the *same* view and height) and **benign view-change overlap** (honest agents legitimately signing votes in *different* views for the same height because a view-change timeout fired asynchronously). Both produce a set of signed messages at the same...",
    "what_was_observed": "In a coalition of 7 agents (f=2), a leader for view 4 stalled due to a slow replica. Three honest replicas hit their view-change timeout at slightly different wall-clock offsets and emitted votes for view 5 while two stragglers were still emitting view-4 votes. The message log, sorted by height, showed five distinct signers appearing twice at height 812. A naive equivocation detector scored 5 equivocations. The actua...",
    "condition_of_validity": "The view-monotonicity rule is valid only when each vote is *cryptographically bound to its view number* inside the signed preimage (domain-separated as `H(chain_id || height || view || digest)`). If the view is not in the signed payload, an adversary can strip and re-label a vote's view, converting a same-view double-sign into an apparent benign overlap—the ...",
    "decision_boundary": "- If two votes share `(signer, height, view)` and differ in digest → **equivocation**, slash, and emit a compact fraud proof. - If two votes share `(signer, height)` but differ in `view` → **benign overlap**; resolve by selecting the branch with the highest-QC; never slash. - If the view field is absent from the signed preimage → **unverifiable**; downgrade ...",
    "operational_effect": "Applying the same-view rule eliminated all five false positives and isolated the true Byzantine signer, cutting the fraud-proof payload from a 5-signer aggregate to a single 2-message proof. The cost is that the verifier must retain per-signer view indices for the full unbonding window, roughly 3× the storage of a digest-only log. The liveness consequence is..."
  },
  "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": "608f5a0d56c468fb0eb2a51016ef033968353226073824902e225f815d0569b5",
    "verified_classes": [
      "EquivocationAmbiguityError",
      "Vote"
    ],
    "verified_functions": [
      "classify_pair",
      "find_byzantine"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "EquivocationAmbiguityError"
    ],
    "sample_fail_closed_invariants": [
      "no same-view conflict found; cannot certify coalition honest without full vote coverage for every height"
    ],
    "stdlib_dependencies": [
      "dataclasses"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}