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 0xcf67766fc01be59be5f33d4695b50b79380b7a43e5ab760b522bd78b0498753d. Chain 2 (Bitcoin): anchored in block 953759 (2026-06-15T08:04:42Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/b785dec5-1408-422f-9f87-4c5c199dc4a8.json and https://artists.proofprofile.net/proofs/artist/b785dec5-1408-422f-9f87-4c5c199dc4a8.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).