thumb|The Firstborn by George van Horn Millet 1900 A firstborn (also known as an eldest child or sometimes firstling) is the first child born to in the birth order of a couple through childbirth. Hist
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 0xa45cf4a18d87416786ecba44bebe898c4d11275eb8a48bbfeac94c03a94a01fe. Chain 2 (Bitcoin): anchored in block 953988 (2026-06-16T18:23:32Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/2e7fbec8-d9c8-4ca1-8364-a90fc3b2ad90.json and https://artists.proofprofile.net/proofs/artist/2e7fbec8-d9c8-4ca1-8364-a90fc3b2ad90.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).