thumb|250px|A whole sheepskin Sheepskin is the hide of a sheep, sometimes also called lambskin. Unlike common leather, sheepskin is tanned with the fleece intact, as in a pelt.Delbridge, Arthur, "The
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 0xfd6939c0e3cd910816b97fd9d0d1de7649742d0ee97a3b540ae39159b0955958. Chain 2 (Bitcoin): anchored in block 954115 (2026-06-17T15:44:10Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/7aeca81e-7b09-46d4-a47d-9a479a282c6d.json and https://artists.proofprofile.net/proofs/artist/7aeca81e-7b09-46d4-a47d-9a479a282c6d.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).