thumb|Leader Pavel Hůla in 2011 The Kocián Quartet is a Czech classical chamber ensemble. Originally named the New String Quartet, it was founded in 1972 by three members of the Prague Symphony Orches
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 0xa89df675ac4fb52ab75f64517991ba6bdeb90e93785072f3ea234f6dfbebbf3d. Chain 2 (Bitcoin): anchored in block 954705 (2026-06-21T13:42:37Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/eebbac2d-c6be-4030-a874-3b475292902c.json and https://artists.proofprofile.net/proofs/artist/eebbac2d-c6be-4030-a874-3b475292902c.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Smetana: String Quartet No. 1 / From My Life - Loudová: String Quartet No. 2 (In One Movement)
String sextet in A Major: I. Allegro vivace
Nikolay Rimsky-Korsakov: String Sextet, Quintet for Piano and Winds, Schéhérazade
1. Confirm isrcCode identifies the recording in the pre-2022 source corpus and cc-db-prod record 2. GET OTSVerificationAPI → server-side canonical-record, hash, and attestation checks must pass 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. Confirm CopyrightID is the CopyrightChains transaction hash 5. If all match: the cc-db-prod record is independently anchored on Bitcoin at OTSTimestamp 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 0x55ca2bdc35f392e0525144ca4f8da540b9af06b4c3ab1607e779e733a32c77ca. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FRP4Y0300170.