Fidelio (; ), originally titled (Leonore, or The Triumph of Marital Love), Op. 72, is the sole opera by German composer Ludwig van Beethoven. The libretto was originally prepared by Joseph Sonnleithn
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 0xe1df4146ae6cf15afb85bf5d2ef8226db50066d89480b282deef2fb666e28b41. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0b14bca9-f733-4874-81b6-5babaaa1e827.json and https://artists.proofprofile.net/proofs/artist/0b14bca9-f733-4874-81b6-5babaaa1e827.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).