Fra is a title of a friar. Fra or FRA may also refer to: Codes fra, the ISO 639-2 code for the French language FRA, the ISO 3166-1 alpha-3 code for France FRA, the IOC country code for France a
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 0xccebc4953d6c04f51e4794c2ecdb213d4bad683904f3fe0bb03f8c65245999b1. Chain 2 (Bitcoin): anchored in block 954705 (2026-06-21T13:42:37Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ee3b7092-854e-43f3-b7d8-a0991f2c48eb.json and https://artists.proofprofile.net/proofs/artist/ee3b7092-854e-43f3-b7d8-a0991f2c48eb.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).