Paul Hammer (13 July 1900 – 25 March 1978) was a Luxembourgish sprinter and long jumper. He competed at the 1920 and the 1924 Summer Olympics. His son, Fred Hammer, was also an athletics Olympian. R
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 0x88cf78397db0c0aacd7068fbecf75b7e21346dd5afac9db73804d4375a593c29. Chain 2 (Bitcoin): anchored in block 954066 (2026-06-17T08:11:48Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/6adbb3cd-c7f1-4663-9a7a-b4c713a286e3.json and https://artists.proofprofile.net/proofs/artist/6adbb3cd-c7f1-4663-9a7a-b4c713a286e3.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.