Slack or Slacks may refer to: Places Slack, West Yorkshire, a village in Calderdale, England Slack (river), a river in Pas-de-Calais department, France The Slack, a village in County Durham, Engla
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 0x86994f08a6fe8e9d358711a7f05ec87c431315919526a3d85cbec33b914e65cd. Chain 2 (Bitcoin): anchored in block 954065 (2026-06-17T08:10:43Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/51103138-83cd-4c2e-b8a0-8afa67d19a75.json and https://artists.proofprofile.net/proofs/artist/51103138-83cd-4c2e-b8a0-8afa67d19a75.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).