thumb|220px|Fernando Aramburu in 2011 Fernando Aramburu (San Sebastián, 1959) is a Spanish writer. He is the author of the novel Patria (English title: "Homeland"), which deals with terrorism in the B
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 0xaf37a322dbdadcee33319b5a6d41754a8bde4fc04cc275da4a17ba7c21bef0b1. Chain 2 (Bitcoin): anchored in block 953736 (2026-06-15T03:21:19Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/98f2badc-9eb4-45d4-925c-97c00786aa79.json and https://artists.proofprofile.net/proofs/artist/98f2badc-9eb4-45d4-925c-97c00786aa79.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.