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 0x41547f81d5e58d6280e2f5b25b1eed0de4787d21c8e1b68bf9181785c9300fa7. Chain 2 (Bitcoin): anchored in block 954615 (2026-06-20T22:44:50Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/c666f0d9-5f3b-4560-9b4f-d3e6d2a64c35.json and https://artists.proofprofile.net/proofs/artist/c666f0d9-5f3b-4560-9b4f-d3e6d2a64c35.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).