thumb|A dark roux in development thumb|A white roux thumb|A roux-based sauce Roux () is a mixture of flour and fat cooked together and used to thicken sauces. Roux is typically made from equal parts
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xda991864113e3754f8ec8543f88ad082d1413112dd08cb88da84443b8b145a74. Chain 2 (Bitcoin): anchored in block 954650 (2026-06-21T04:51:12Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/da088f8d-2095-4cc5-8408-f3ed73d99da5.json and https://artists.proofprofile.net/proofs/artist/da088f8d-2095-4cc5-8408-f3ed73d99da5.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).