Biba was a London fashion store of the 1960s and 1970s. Biba was started and run by the Polish-born Barbara Hulanicki and her husband Stephen Fitz-Simon. After the original company closed in 1975, Bi
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 0x8abc3658bd4925585cd7c1ab45d837f05ab66c47ebe7c003e6acd320dbe8903b. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/df74a5c4-4322-45ee-91de-68a0f890ff64.json and https://artists.proofprofile.net/proofs/artist/df74a5c4-4322-45ee-91de-68a0f890ff64.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).