thumb|Issay Dobrowen in 1931 Issay Alexandrovich Dobrowen (; 9 December 1953), born Itschok Zorachovitch Barabeitchik (), was a Russian and Norwegian pianist, composer and conductor. He left Russia
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 0x9d60a0b5c75e9b22cd12c74e104c5a1c7a61890b7506508993612ecb4d83c33d. Chain 2 (Bitcoin): anchored in block 954008 (2026-06-16T21:31:27Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/335bb82e-c1a9-47ff-98ab-c1ded1587e61.json and https://artists.proofprofile.net/proofs/artist/335bb82e-c1a9-47ff-98ab-c1ded1587e61.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.