Marco Antônio de Oliveira Maciel (21 July 1940 – 12 June 2021)Aos 80 anos, morre o ex-vice-presidente Marco Maciel was a Brazilian politician, lawyer, and law school professor who served as the 22nd
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 0xd1a5ac7a0703e5f805f1572a8d0457fa1a42e8af7b667c3fe2f7e132caf3ec56. Chain 2 (Bitcoin): anchored in block 953924 (2026-06-16T09:52:28Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/1d441d01-ba34-4071-ac63-5195b03a0a6d.json and https://artists.proofprofile.net/proofs/artist/1d441d01-ba34-4071-ac63-5195b03a0a6d.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).