Fredrik Ullén (born 13 April 1968 in Västerås, Sweden) is a Swedish cognitive neuroscientist and concert pianist. He is internationally known for his recordings of complex piano repertoire — includi
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 0x3939266aa5ea2e8ace35c7537653b3069234fc9e6b6cbbf4162d233a59bb048a. Chain 2 (Bitcoin): anchored in block 954742 (2026-06-21T20:46:40Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/fe423669-45fd-403a-9e8a-4aeda89552e0.json and https://artists.proofprofile.net/proofs/artist/fe423669-45fd-403a-9e8a-4aeda89552e0.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Sorabji, K.: 100 Transcendental Studies, Nos. 26-43