David or Dave Black may refer to: Dave Black (baseball) (1892–1936), American baseball player Dave Black (drummer) (1928–2006), American jazz drummer Dave Black (composer) (born 1959), American author
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 0x73143266c1a0ef8b8c271951c32f8574d14c084763535d5d1cfa2c6a95a4539f. Chain 2 (Bitcoin): anchored in block 954667 (2026-06-21T07:29:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/b7c8b64d-4024-4715-b75e-72c26d28016c.json and https://artists.proofprofile.net/proofs/artist/b7c8b64d-4024-4715-b75e-72c26d28016c.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).