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 0x96dfa1a7b4cd258034e9e2cc96a8bd44519a4e46add77ae2c90b39c4d5af3074. Chain 2 (Bitcoin): anchored in block 953976 (2026-06-16T16:55:36Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/2b04c988-e7c8-427c-b3c9-5de2f15e7a28.json and https://artists.proofprofile.net/proofs/artist/2b04c988-e7c8-427c-b3c9-5de2f15e7a28.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).