right|thumb|The cellarium of Fountains Abbey, England A cellarium (from the Latin cella, "pantry"), also known as an undercroft, was a storehouse or storeroom, usually in a medieval monastery or castl
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 0x87fa3e956afead0caebeab3b1041e0c4f3a0ed1b155e85b5837718c98a34c1f8. Chain 2 (Bitcoin): anchored in block 954066 (2026-06-17T08:11:48Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/714e5f4f-9864-44bb-bfa9-c48c8d788313.json and https://artists.proofprofile.net/proofs/artist/714e5f4f-9864-44bb-bfa9-c48c8d788313.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).