Marcos António da Fonseca Portugal (24 March 1762 – 17 February 1830), also known as Marco Portogallo in Italian, was a Portuguese-Brazilian classical composer, who achieved great international fame f
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 0x17479b47d94ab61372ba6292ab28a74a32a90a9a547edbaede50651ae8141b4c. Chain 2 (Bitcoin): anchored in block 954689 (2026-06-21T10:35:31Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/e33ce8eb-1a97-4ba0-ab56-5a447144481e.json and https://artists.proofprofile.net/proofs/artist/e33ce8eb-1a97-4ba0-ab56-5a447144481e.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Marcos Portugal: Missa Grande (Great Mass)
Portugal: Matinas do Natal, Rio de Janeiro 1811
Marcos Portugal: Música Religiosa Publicada no Século XIX