right|thumb|Eduard Haken Eduard Haken (22 March 1910 – 12 January 1996 in Prague) was a Czech operatic bass who had a lengthy career at the National Theatre in Prague during the 20th century. Although
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 0xcd0d92ea3bd8c7e6a75384e71fe579d07016835dd106910e376c6eec0989ffc0. Chain 2 (Bitcoin): anchored in block 954650 (2026-06-21T04:51:12Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/daa926a3-7981-4a47-9940-8012131e00cf.json and https://artists.proofprofile.net/proofs/artist/daa926a3-7981-4a47-9940-8012131e00cf.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Operatic Recital / Dvořák, Smetana, Tchaikovsky, Verdi