thumb|upright=1.4|Thule as Tile on the Carta marina of 1539 by Olaus Magnus, where it is shown located to the northwest of the Orkney islands, with a "monster, seen in 1537", a whale ("balena"), and a
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 0x87dd989a77e399876a26e4c646b741a0be9827687fd0b0729cd3d2f76af83946. 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/f934e62d-ef2d-40a8-ba93-40abe485599c.json and https://artists.proofprofile.net/proofs/artist/f934e62d-ef2d-40a8-ba93-40abe485599c.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).