Alberto Contreras (died 1958) was a Spanish-born stage and film actor who settled in Argentina.Richard p.96 He portrayed don Florín in the play La sirena varada, written by Alejandro Casona. Selected
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 0xa9d4c79140c7843bea9c875c5d2ae2d0b831e7c8a316dfa3f3aa5b124ed17d83. Chain 2 (Bitcoin): anchored in block 953423 (2026-06-12T21:20:00Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/3907b5c8-ebd2-4676-a332-02c25fd3cfdf.json and https://artists.proofprofile.net/proofs/artist/3907b5c8-ebd2-4676-a332-02c25fd3cfdf.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).