Greta Kraus (3 August 1907 – 30 May 1998) was a Canadian pianist, harpsichordist and music teacher of Austrian origin. Life alt=Portrait of Greta Kraus, taken in Vienna in June 1974|thumb|Greta Kra
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 0xc55619eeeff3e3de9da5aa259a15dbfcf6d4e6e2fb16d6fcceb53a7ade5bc09b. Chain 2 (Bitcoin): anchored in block 954784 (2026-06-22T02:53:59Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/f4c4c919-da26-485c-9960-7df091db7f34.json and https://artists.proofprofile.net/proofs/artist/f4c4c919-da26-485c-9960-7df091db7f34.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).