CR2 may refer to: CR2 battery, a dry-cell type battery commonly used in cameras CR2, a raw image format used by Canon digital cameras CR2, a postcode district in the CR postcode area CR2, a colla
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 0xb5a6afb7804b814e45d23ec24d08f6199eec9f1a3de854cda4952d1526ab1bf2. Chain 2 (Bitcoin): anchored in block 953626 (2026-06-14T11:41:45Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/2f068f1d-bc10-4692-a742-2155bb85c3ce.json and https://artists.proofprofile.net/proofs/artist/2f068f1d-bc10-4692-a742-2155bb85c3ce.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).