thumb|right|upright=1.35|Landers, California at nautical dusk (20-second exposure) Dusk occurs at the darkest stage of twilight, or at the very end of astronomical twilight after sunset and just befo
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 0xea01a7750b7a03a1a14437429124932fa25c23ac8c32de98d901987cac474199. 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/bcc61174-9958-4e1c-8bc9-c76eed8d1328.json and https://artists.proofprofile.net/proofs/artist/bcc61174-9958-4e1c-8bc9-c76eed8d1328.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).