Henry Grossman (October 11, 1936 – November 27, 2022) was an American photographer, best known for his portraits of notable figures, in particular President John F. Kennedy and The Beatles, as well as
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7f539a63249b832758912e6bd1ef11a38f426599c038a3b9370b43d94bb4c424. 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/2f7483c0-16e3-4e5c-b70e-2196878c9e14.json and https://artists.proofprofile.net/proofs/artist/2f7483c0-16e3-4e5c-b70e-2196878c9e14.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).