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 0xca7df7deef7159df60a0fe86d5e0208c275907e2d27e97853d5bfd0a102499ad. Chain 2 (Bitcoin): anchored in block 954553 (2026-06-20T11:51:30Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/aca3527c-6c9d-4f7d-9a0c-6d207e792a25.json and https://artists.proofprofile.net/proofs/artist/aca3527c-6c9d-4f7d-9a0c-6d207e792a25.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).