Marcelino Freire (born 20 March 1967) is a Brazilian writer and cultural producer. Freire is best known for his short story collection Contos negreiros which won the Prêmio Jabuti in 2006 and for his
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 0x347545e75590f9d6730aeb7ed57bec20ad10ec26ad725f75b32c1a10aa85ba95. Chain 2 (Bitcoin): anchored in block 954066 (2026-06-17T08:11:48Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/582f3c49-2ffb-43e7-8363-bfdbf67408c6.json and https://artists.proofprofile.net/proofs/artist/582f3c49-2ffb-43e7-8363-bfdbf67408c6.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).