Trio de Ouro (Gold Trio) was a Brazilian vocal group formed by Herivelto Martins in 1937. They performed regularly at the Cassino da Urca. The trio was composed of two men and one woman, who, through
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 0x156626bd737e216f13bd8fb48047c72ab892fb5af395b28e134b732deb5a59bf. Chain 2 (Bitcoin): anchored in block 953899 (2026-06-16T06:37:25Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/129fb0b4-30fe-4b1b-a987-f2cd160b3be8.json and https://artists.proofprofile.net/proofs/artist/129fb0b4-30fe-4b1b-a987-f2cd160b3be8.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).