is a former Japanese football player and manager. He played for Japan national team. Club career Matsuura was born in Yokohama on November 20, 1955. After graduating from Waseda University, he joine
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 0xd057b958a20c3ac3f13ea205cd9fc27a5b27724c5941932bfdc7285d3fba4a15. Chain 2 (Bitcoin): anchored in block 954043 (2026-06-17T04:15:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/3eefb1d4-4f58-49a4-b659-7a4d846db1ef.json and https://artists.proofprofile.net/proofs/artist/3eefb1d4-4f58-49a4-b659-7a4d846db1ef.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).