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 0xf19fb07e166209f4d81427a50cf911ae0d4218f92e5d5f8aec9b661425e957f1. Chain 2 (Bitcoin): anchored in block 954667 (2026-06-21T07:29:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ca056c0b-eb71-4e8c-9eb1-8d1d3b5b110e.json and https://artists.proofprofile.net/proofs/artist/ca056c0b-eb71-4e8c-9eb1-8d1d3b5b110e.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Anna Serova Plays the 1615 Amati Viola 'La Stauffer' (Viola Collection)
Walton: Cello Concerto (Arr. for Viola & Orchestra by Anna Serova) - Roberto Molinelli: Lady Walton's Garden