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 0xd26e8df2de9f4a9e1ac9dfab0fe4e2c849efe1abbb6d1d82cdf2f0e030df89f9. Chain 2 (Bitcoin): anchored in block 953938 (2026-06-16T11:35:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/2085fb85-df14-46ea-ac96-d68e624e25bd.json and https://artists.proofprofile.net/proofs/artist/2085fb85-df14-46ea-ac96-d68e624e25bd.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).