thumb|Kit Armstrong in 2014 Kit Armstrong (, born March 5, 1992) is an American classical pianist, composer, organist, and former child prodigy of British-Taiwanese parentage. Education Armstrong w
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 0x9f6e4c6de7850c15cd25e59f7c8e76846ff462e33d70047e200197dc81513312. 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/2c908cc5-9346-4acc-982d-291044f4eccf.json and https://artists.proofprofile.net/proofs/artist/2c908cc5-9346-4acc-982d-291044f4eccf.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
William Byrd & John Bull: The Visionaries of Piano Music
Prelude "Laet ons met herten reijne" (MB 14/56; BL Add. MS 23623 f. 65)
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 0xfc5ca7f3a0a92051a38b4bced1bd51fb5ba067c798c77a42ee4daf7f98023369. Chain 2 (Bitcoin): anchored in block 960381 (2026-07-31T09:50:11Z), 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/DEN962031212.
Violin Sonata in C Major, K. 296: I. Allegro vivace
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf8e8605f6b9a8ab2c0e55d0bdb405d1aeb2100fbbc5311748fcfc55a96a23a0b. Chain 2 (Bitcoin): anchored in block 960106 (2026-07-29T12:41:21Z), 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/DEN962300941.
Violin Sonata in C Major, K. 296: II. Andante sostenuto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf20f30f997658ac40888f385671d73e80180ea72660693d7d0f07cd4f22d3b47. Chain 2 (Bitcoin): anchored in block 956889 (2026-07-06T06:56:49Z), 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/DEN962300942.
Violin Sonata in C Major, K. 296: III. Rondeau. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x67d272706559a27cc32f26860fc4aa5c3bd1e1271f7c9df0e873efbc2f66beb4. 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/DEN962300943.
Violin Sonata in G Major, K. 301: I. Allegro con spirito
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcd7b5f18ce702cd46efe96284f4f972263ca2514942f47d0a77b7087c2f3c5e0. Chain 2 (Bitcoin): anchored in block 960105 (2026-07-29T12:35:17Z), 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/DEN962300951.
Violin Sonata in G Major, K. 301: II. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x88faa34f999891946d06230e6a7ef62955afe40be6fa086b114e49d1285c600e. Chain 2 (Bitcoin): anchored in block 960113 (2026-07-29T13:38:16Z), 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/DEN962300952.
Violin Sonata in E-Flat Major, K. 302: I. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa6ee68b113b7006145e94c5432adb8a1c0f429db2baa0fadd7ae627eb5b1196e. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/DEN962300961.
Violin Sonata in E-Flat Major, K. 302: II. Rondeau. Andante grazioso
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa7d9cb796b81ca8f719296ab123765dddc922a1f590fa37f686ba6aef036a3e1. Chain 2 (Bitcoin): anchored in block 960138 (2026-07-29T19:35:34Z), 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/DEN962300962.
Violin Sonata in C Major, K. 303: I. Adagio - Molto allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x73078e347e688d10451ce51f82f359c0378720cd2c19988a9ed0f4c6681d0491. Chain 2 (Bitcoin): anchored in block 960111 (2026-07-29T13:21:01Z), 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/DEN962300971.
Violin Sonata in C Major, K. 303: II. Tempo di menuetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x145d8d37b2625fc3f3adb601adf58650ea532fbee9d91c2878f353d4f9172fac. Chain 2 (Bitcoin): anchored in block 960175 (2026-07-30T00:16:15Z), 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/DEN962300972.
Violin Sonata in E Minor, K. 304: I. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfc98a9b8f1d56689876d1ffbaaf83182fcde11175a28bf06f215b0acb6941e4a. Chain 2 (Bitcoin): anchored in block 960144 (2026-07-29T21:09:47Z), 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/DEN962300981.
Violin Sonata in E Minor, K. 304: II. Tempo di menuetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb6eb0e76c6d2db612e42e236f03ac01d3fa7e4b9e97008ba2c74d667d3e8d3b3. 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/DEN962300982.
Violin Sonata in A Major, K. 305: I. Allegro di molto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x315329bc8f5283a8c985dcf89d11f8cd930a17fe73eb260e0de9813b0300f723. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/DEN962300991.
Violin Sonata in A Major, K. 305: IIa. Thema. Andante grazioso
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xce121db8870f02500958d7c400cf6bcbf5f70d3d66f3cc739afe7a7a8753f3da. Chain 2 (Bitcoin): anchored in block 960173 (2026-07-30T00:11:40Z), 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/DEN962301131.
Violin Sonata in A Major, K. 305: IIb. Var. 1 (violino tacet)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x80c97d9d83e07145d432846617f82cc5dc0cb46113a5c6f2b7591023bea2ff0f. Chain 2 (Bitcoin): anchored in block 960291 (2026-07-30T18:23:33Z), 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/DEN962301132.
Violin Sonata in A Major, K. 305: IIc. Var. 2
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x00d0aac88f0e32fb7c0026d3157291967f4f3da8b8d97d72b056f845d6010d5e. Chain 2 (Bitcoin): anchored in block 960284 (2026-07-30T17:23:26Z), 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/DEN962301133.
Violin Sonata in A Major, K. 305: IId. Var. 3
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb54fe8e8b3f887315be3b11309977ca5f86126b50b6936065e40d69d045d18a6. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/DEN962301134.
Violin Sonata in A Major, K. 305: IIe. Var. 4
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5e433b9c6d180ad52c1db7737072849107d7473e7a877e9b74cb1e1b2b18bfe5. Chain 2 (Bitcoin): anchored in block 960220 (2026-07-30T07:28:30Z), 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/DEN962301135.
Violin Sonata in A Major, K. 305: IIf. Var. 5
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb0263956f720ddbb30c8e9a16754e99d27ee262e21580def181e6f999771d5ef. Chain 2 (Bitcoin): anchored in block 960250 (2026-07-30T11:13:28Z), 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/DEN962301136.
Violin Sonata in A Major, K. 305: IIg. Var. 6. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe29da452650f323a5b2c42d7cf9b7d90b3667c198a244c7d088108a329ccd7b9. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/DEN962301137.