CAIN-42 PBFT quorum-certificate evidence: partition-test-2026-09-26
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What: Every quorum certificate held by each replica of cain-mr-01 after two network partitions made by taking a host's WireGuard link down while its replicas kept running: a 1-replica host isolated (the majority keeps committing; the isolated replica, still running, commits nothing), and a 2|2 split (neither side commits). Identical decision chains on all four replicas show there was no fork.
Classification: MEASURED on the live multi-region cluster cain-mr-01 during network-partition tests
Generated: 2026-09-26T21:18:47Z
Source commitment: git 81bdf8418178750be8def719d38c6739d291d0c5 (engine 33.4-production-hardened); source is not published.

Verify in about 30 seconds (Python 3.8+, `pip install cryptography`, no CAIN code):

  BASE=https://cainstudio.online/proof/bundle/partition-test-2026-09-26/      # or https://mcpgate.online/proof/bundle/partition-test-2026-09-26/
                                                             # or https://clawx.click/evidence/partition-test-2026-09-26/
  curl -so verify_pbft_qc_bundle.py "$BASE/verify_pbft_qc_bundle.py.txt"
  curl -so PBFT_QC_BUNDLE.json "$BASE/PBFT_QC_BUNDLE.json"
  sha256sum PBFT_QC_BUNDLE.json verify_pbft_qc_bundle.py
    # expect 1f1d7d4a3af89f9f710aedc574a191048a5c1d7655513c185443f4135ea478c8  PBFT_QC_BUNDLE.json
    # expect ba452ce42528f11f7f5235727a65cae25a34072bc52b4711fd72581615d06009  verify_pbft_qc_bundle.py
  python3 verify_pbft_qc_bundle.py PBFT_QC_BUNDLE.json

Or open $BASE/index.html: your browser runs the same checks (WebCrypto Ed25519).

Read the verifier before trusting it: it is about 300 lines. It tampers with a certificate
in seven ways and requires every tampered copy to fail, so a verifier that accepts
everything would not pass.

Not claimed: partitions other than whole-host link loss (no asymmetric or flapping partitions); independent operators or providers; physical key placement (operator-attested); third-party review; absence of bugs.