right|thumb|Pongee umbrella thumb| of Ushikubi, showing slubs Pongee is a type of slub-woven fabric, created by weaving with yarns that have been spun by varying the tightness of the yarn's twist at v
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 0xf90d5923a3a0cf0e399033937ab5a18abe1b42d800b114c31c83210a410c8591. 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/6f309dd9-4c5b-46ae-86bb-7d34559488c3.json and https://artists.proofprofile.net/proofs/artist/6f309dd9-4c5b-46ae-86bb-7d34559488c3.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).