thumb|220px|Rudolf Koelman in 2017 Rudolf Koelman (born 1959 in Amsterdam) is a Dutch violinist and is professor for violin at the Zürcher Hochschule der Künste (ZHdK) in Switzerland. Biography Koel
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbfcb48436d235996f34606ea27c8774baef1c0e68e665653cad3ae13bb18888b. 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/e13c926f-e191-4bd3-9da9-43808b94cab9.json and https://artists.proofprofile.net/proofs/artist/e13c926f-e191-4bd3-9da9-43808b94cab9.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Violin Concerto No. 3 in B Minor, Op. 61: II. Andantino quasi Allegretto
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x60fa419ef76a63927fed97ab869a5baec30cd0cc30e1c76f8562a30ae88d2ec1. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/NLB152300480.
Violin Concerto No. 1 in D Major, Op. 6: I. Allegro maestoso
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6ef369a3e207423964c1b80e4e1081fbee761036ad77a3d6600f02855cf8a343. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/NLB150900661.
Violin Concerto No. 1 in D Major, Op. 6: II. Adagio
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb54fb3c00c2ea40071ca844955a4f5f3959f9450e07f9637e5cf95f8e60d0dee. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/NLB150900662.
Violin Concerto No. 1 in D Major, Op. 6: III. Rondo, allegro spirituoso
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3012bdb734e63f3ad084b4358b1c26e4b054858e4d19d346fbb34a875617c89c. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/NLB150900663.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xce5e945304856b283b65f4568ed61dfd7eba7526d2a819d1aaf47395fb591f79. Chain 2 (Bitcoin): anchored in block 956312 (2026-07-02T05:09:12Z), 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/NLB150900664.
Violin Concerto No. 2 in B Minor, Op. 7, "La campanella": I. Allegro maestoso
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x31875efaaffd2dcab62e9d1ad76110f18dc012287b0d8762bd3dd27027c23da5. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/NLB150900665.
Violin Concerto No. 2 in B Minor, Op. 7, "La campanella": II. Adagio
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb7401e3bc8e6affc415e753c165a4063ec3568eab347325c3820fa2063b05824. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/NLB150900666.
Violin Concerto No. 2 in B Minor, Op. 7, "La campanella": III. Rondo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x512c504b4406a7789d37ed31f22c457f1b08e0b20ac5f6f61e163b7047d7f7f0. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/NLB150900667.