Blue Orange is a French board game company based in Pont-à-Mousson, France. The company is often called Blue Orange international or Blue Orange Europe and mistaken for Blue Orange Games.; thumb|220
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 0xe485796d943149fba6538b34f2097f4008eca9f9b64deb48e7fbfbf27700247f. Chain 2 (Bitcoin): anchored in block 954050 (2026-06-17T05:14:33Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/42959d12-bcdf-47f8-91e2-1eb5b9b2ef5b.json and https://artists.proofprofile.net/proofs/artist/42959d12-bcdf-47f8-91e2-1eb5b9b2ef5b.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.