CAIN-42 PBFT quorum-certificate evidence: degraded-network-2026-09-27
=========================================================================

What: Every quorum certificate held by each replica after 240 s of 'delay 120ms 40ms distribution normal loss 10% duplicate 5% reorder 10% 50%' on all four replicas' mesh traffic.
Classification: MEASURED on the live 4-server cluster cain-mr-02 under packet loss, delay, jitter, duplication and reordering
Generated: 2026-09-27T03:42:53Z
Source commitment: git 521f84c0456bf118645722073f09df140167b16b (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/degraded-network-2026-09-27/      # or https://mcpgate.online/proof/bundle/degraded-network-2026-09-27/
                                                             # or https://clawx.click/evidence/degraded-network-2026-09-27/
  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 405e189d2ab18bbb435f10380174afc2db354d45f062ac4fe663ee2448f2d562  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: impairments beyond the stated parameters; flapping links or long partitions (see the partition bundles); latency numbers as a guarantee (one client host); independent operators or providers; third-party review.