Jan Larsen may refer to: Jan Larsen (footballer) (1945–1993), Danish football defender Jan Larsen (darts player) (born 1954), Danish darts player Jan Larsen (swimmer) (born 1967), Danish swimmer
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 0xa52f371d0f9e46d4cda88e8e65aa3fc6540e79a5942af0e5ff836bf52402477b. Chain 2 (Bitcoin): anchored in block 954065 (2026-06-17T08:10:43Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/4aef0420-cbe7-44c2-a94d-79579c1718d6.json and https://artists.proofprofile.net/proofs/artist/4aef0420-cbe7-44c2-a94d-79579c1718d6.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).