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 0xa9e0456b1b24ea0fc4e3119128e48ab919b342b688d3b8659910e7484f43103f. Chain 2 (Bitcoin): anchored in block 954062 (2026-06-17T07:39:10Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/46086b0e-1ca8-4f87-8651-31cbc4db2764.json and https://artists.proofprofile.net/proofs/artist/46086b0e-1ca8-4f87-8651-31cbc4db2764.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
Bruch: Violin Concerto No. 1 - Kreisler: Transcriptions for Violin & Orchestra
Bruch, Dvořák, & Goldmark: Violin Concertos - Kreisler: Transcriptions
Mendelssohn & Paganini: Violin Concertos