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 0xa3b2e205af4c4cc9aadf45e51f27afc6c93c35a8628f46fca0460b73808d7929. 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/3396bb9f-1c19-4bf9-9bfd-7838bf20bfe8.json and https://artists.proofprofile.net/proofs/artist/3396bb9f-1c19-4bf9-9bfd-7838bf20bfe8.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
Creak-whoosh (Estonian, Ingrian and Votian song re-imagined in Australia by Olev Muska and Mihkel Tartu)