The Porter Brook is a river which flows through the City of Sheffield, England, descending over from its source on Burbage Moor to the west of the city to its mouth where it joins the River Sheaf in
1. Compute SHA-256 of OTSCanonicalRecord value → must equal OTSHash 2. Open OTSProofURL → extract Bitcoin block number → must equal OTSBitcoinBlock 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Read CopyrightID inside OTSCanonicalRecord → must equal the CopyrightID above 5. GET OTSVerificationAPI → pre-computed 6-check result from server 6. If all match: this entity was registered on CopyrightChains at OTSTimestamp, independently verifiable on Bitcoin Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc470b2718d4ca996f3088ad896ab77823bde01b8ca34f8c58a801b545d5c8685. Chain 2 (Bitcoin): anchored in block 953899 (2026-06-16T06:37:25Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/1281705b-1b52-411e-8a38-b1c846646fb6.json and https://artists.proofprofile.net/proofs/artist/1281705b-1b52-411e-8a38-b1c846646fb6.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).