Dutra may refer to: Places Astolfo Dutra, a Brazilian municipality in the state of Minas Gerais Cidade Dutra (district of São Paulo), a district within the city of São Paulo Presidente Dutra, Mara
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 0xd431f801c6b1ca3ccf296cf1f3322756050aae7ad1a2aea90be9ef47ddffa873. Chain 2 (Bitcoin): anchored in block 953968 (2026-06-16T16:01:49Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/2977d403-c65c-4f4b-8529-a2148383f11f.json and https://artists.proofprofile.net/proofs/artist/2977d403-c65c-4f4b-8529-a2148383f11f.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).