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 0x943121cf1071068e2457b4fe3ef2ddf5ee89a4791c1d4d9d7011a8b10137cc76. Chain 2 (Bitcoin): anchored in block 954131 (2026-06-17T19:19:19Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/7ddc3281-e803-49d1-ba34-e93dfe39628b.json and https://artists.proofprofile.net/proofs/artist/7ddc3281-e803-49d1-ba34-e93dfe39628b.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).