thumb|Cruz in interview on TV3 in 2022 Antonio Cruz Llauna (14 July 1946 – 11 July 2025), known as Toni Cruz, was a Spanish television producer and singer. He was a member of the musical group . Lif
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 0xb685e70896dd851ddec9e223e91703691cde0d05e057d910bf9d6469f7fe2bba. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0eba718f-2442-4210-ba8c-81556f81bcfc.json and https://artists.proofprofile.net/proofs/artist/0eba718f-2442-4210-ba8c-81556f81bcfc.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).