Per Nilsen (born April 8, 1960) is a Swedish professor and author. He grew up in Täby, north of Stockholm. Nilsen graduated in economics at the Stockholm School of Economics in 1985. He has written su
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 0x4d4fb0565cb515dd9798eabbad4fe9658f969bfdd6b94801b0019663731ad560. Chain 2 (Bitcoin): anchored in block 954631 (2026-06-21T02:46:24Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/d17e1bbc-294b-4ced-a877-68a24ad90e2e.json and https://artists.proofprofile.net/proofs/artist/d17e1bbc-294b-4ced-a877-68a24ad90e2e.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.