Tag, TAG, or tagging may refer to: Identification and tracking Tag (graffiti), a form of graffiti signature Dog tag, an ID tag worn by military personnel Ear tag, an ID tag worn by farm animals
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 0x1a182979df8e9c39c8bfa5b1105f7bebff4ffc453eb7b7e1b819f0e25836ce44. Chain 2 (Bitcoin): anchored in block 953713 (2026-06-15T00:33:41Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/7fff8dd7-d36a-4cfc-b4f0-1cadf46b8a65.json and https://artists.proofprofile.net/proofs/artist/7fff8dd7-d36a-4cfc-b4f0-1cadf46b8a65.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).