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 0x68c1f477f748473a5cfeb19d60e3aa29a1456a6d7a931bc5a65f7a6e09eee988. Chain 2 (Bitcoin): anchored in block 953714 (2026-06-15T00:43:59Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/85c77a2c-91cd-4e92-8ab3-4f30433487a5.json and https://artists.proofprofile.net/proofs/artist/85c77a2c-91cd-4e92-8ab3-4f30433487a5.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
V.A. of Progressive House (Underground Beats Compilation)