right|thumb|300px|Bruce Stark caricatured the cast of Hill Street Blues for the cover of the June 1, 1985 issue of TV Guide. Bruce Stark (1933 - December 29, 2012) was an American artist noted for his
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 0xa345346b7d0c5fff1abbe6f613553f5e26250d72b2e6a1d04a944ae516fe3367. Chain 2 (Bitcoin): anchored in block 954784 (2026-06-22T02:53:59Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ff9a81a0-59df-4647-989f-8d091ff4c777.json and https://artists.proofprofile.net/proofs/artist/ff9a81a0-59df-4647-989f-8d091ff4c777.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Stark, B.: American Suite / 5 Preludes / Fugue, Interlude and Finale / Songs of Innocence