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 0x021ccc7bcca50dcb62b4bdc8cb2d7fe825a187056acd23685b4d0342d7b2aa21. Chain 2 (Bitcoin): anchored in block 953991 (2026-06-16T18:47:23Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/2ed9d87f-2ce2-4bd0-bf96-7d9b8632a8e0.json and https://artists.proofprofile.net/proofs/artist/2ed9d87f-2ce2-4bd0-bf96-7d9b8632a8e0.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.