thumb|African Rose plums (Japanese or Chinese plum) A plum is a fruit of some species in Prunus subg. Prunus. Dried plums are usually called prunes. thumb|Plum flowers thumb|180px|Plum unripe fruits
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 0x84071110723051a0ec59b911feb8625b14b49a927a77d380d6ac74a1bf744986. Chain 2 (Bitcoin): anchored in block 954728 (2026-06-21T18:08:38Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/fbb04bf9-b8a0-4cec-97e2-dd6c3f7a85d2.json and https://artists.proofprofile.net/proofs/artist/fbb04bf9-b8a0-4cec-97e2-dd6c3f7a85d2.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).