thumb| cloth, probably 1950s is a type of silk fabric traditionally produced in Japan; it is durable, hard-faced, and somewhat stiff, with a slight sheen, and slubbiness is deliberately emphasised.
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 0x54ed11b1e284ab2dfbcb6a6dd5c6a98195a3ead46479c4f49af52b27d40d39b0. Chain 2 (Bitcoin): anchored in block 954025 (2026-06-17T00:32:47Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/38744abf-834d-4fdd-a785-d55effdaf94e.json and https://artists.proofprofile.net/proofs/artist/38744abf-834d-4fdd-a785-d55effdaf94e.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.