Thirteen or 13 may refer to: 13 (number), the natural number following 12 and preceding 14 Any of the years 13 BC, AD 13, 1913, or 2013 Music Albums 13 (Black Sabbath album), 2013 13 (Blur albu
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 0xb1576534b5d8e04f5fef98b721645bd981f4337e46e26bf11cad8890e0952e74. Chain 2 (Bitcoin): anchored in block 954631 (2026-06-21T02:46:24Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/d1118279-6398-48af-9cb0-3860aa5ddef9.json and https://artists.proofprofile.net/proofs/artist/d1118279-6398-48af-9cb0-3860aa5ddef9.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).