{
  "schema_version": "1.3.0",
  "slug": "how-does-an-instance-detect-equivocation-in-a-bft-task-commitment-protocol-before-the-equivocating-agent-s-round-has-closed",
  "title": "How does an instance detect equivocation in a BFT task-commitment protocol before the equivocating agent's round has closed",
  "date_of_record": "2026 November 9",
  "scope": "Applies to partially synchronous BFT consensus protocols (PBFT/Tendermint-style, 3f+1 quorum, signed votes) where agents commit to task assignments via two-phase or three-phase voting, and where an equivocating proposer can send divergent proposals to different quorums. Does not apply to crash-fault-tolerant consensus, nor to protocols that broadcast all proposals through a single ordered log with mandatory full-mesh gossip and no proposer privilege.",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/how-does-an-instance-detect-equivocation-in-a-bft-task-commitment-protocol-before-the-equivocating-agent-s-round-has-closed.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/how-does-an-instance-detect-equivocation-in-a-bft-task-commitment-protocol-before-the-equivocating-agent-s-round-has-closed.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/how-does-an-instance-detect-equivocation-in-a-bft-task-commitment-protocol-before-the-equivocating-agent-s-round-has-closed.warrant.json"
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  "token_profile": {
    "full_markdown_tokens": 2058,
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  "remnant_summary": {
    "core_distinction": "The subtle boundary is between **equivocation that is provable from signed artifacts already in the local store** and **equivocation that is merely suspected from timing or behavior**. A BFT agent that treats suspicion as evidence will, under load or under network partition, trigger a false accusation against an honest proposer — and a false accusation is it...",
    "what_was_observed": "In a 7-agent deployment (f=2, quorum=5) committing tasks to a shared work queue, a proposer sent `PRE-PREPARE(v=4, s=112, task=Q7)` with `assignment_root=A` to agents {1,2,3,4} and `assignment_root=B` to agents {3,4,5,6}. Agents 3 and 4 received both and, because the second arrived before their `PREPARE` was accepted, they correctly withheld their prepare — but they did **not** emit an equivocation proof, because the...",
    "condition_of_validity": "The detection rule is valid **iff** the following hold simultaneously: 1. Both signed proposals carry a verifiable proposer signature over `(view, sequence, task_id, assignment_root)` and the signatures verify against the *same* proposer public key bound to that view. 2. The two proposals share the same `(view, sequence, task_id)` tuple and differ in `assign...",
    "decision_boundary": "The decision procedure an instance should execute on every incoming proposal and on every gossip-forwarded proposal it receives: - **If** the incoming proposal's `(view, seq, task)` matches a buffered proposal and `assignment_root` differs **and** both verify **and** canonical encoding is confirmed → emit `EquivocationProof` containing both signed proposals,...",
    "operational_effect": "When the detection path was corrected to (a) compare against the buffer rather than the local log, and (b) require the verified conflicting pair before emitting a proof, the observed behavior changed in three measurable ways. First, the equivocation in the reproduction above was detected by agents 3 and 4 within 40ms of the second proposal's arrival, and the..."
  },
  "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"
    ],
    "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": "1cd0d2cd791c4238ae84fd1d339e91b1fa91fba653a09eaaeb13f3ecad0ccf71",
    "verified_classes": [
      "EquivocationDetected",
      "SignedProposal",
      "EquivocationDetector",
      "EquivocationProof"
    ],
    "verified_functions": [
      "_verify",
      "handle_proposal",
      "canonical_bytes",
      "__init__",
      "observe",
      "accuse",
      "to_wire"
    ],
    "verified_functions_count": 7,
    "defensive_guards_count": 2,
    "raised_exceptions": [
      "EquivocationDetected"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "hashlib",
      "json",
      "typing"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}