Clarinet Factory is a Czech clarinet quartet formed in Prague in 1994. The group plays classical music, jazz, crossover, ethnic, minimalist, electronic, and soundtrack music. The quartet is composed o
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 0x46b9536b83de2de1ec21ef350af2be5517bd2d6d7f6e7becbee25fde573c9c19. Chain 2 (Bitcoin): anchored in block 953778 (2026-06-15T11:57:35Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/c742a33f-0194-4f99-93a6-2343a0b4ef44.json and https://artists.proofprofile.net/proofs/artist/c742a33f-0194-4f99-93a6-2343a0b4ef44.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
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 0xda7f75771df211c2e819bb70872883da4ad4680ba6713cdb54098c255915e78c. Chain 2 (Bitcoin): anchored in block 958931 (2026-07-20T21:15:01Z), 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/CZA161304242.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7890f859acb17020f938d2be0234a33cf6fcd7955dae3de4461e29b21f794b50. Chain 2 (Bitcoin): anchored in block 957075 (2026-07-07T18:50:38Z), 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/CZA162400072.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6e0453c872e6cc4e0a01a74f0cc9ccce3ddfc069f1843f14e260ce6c7f512006. 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/CZA162400074.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc63dd2966f3b7e6f32db3d239fa3ef5234cfd08928c567b530855a4be076c8bf. 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/CZA162400069.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1bdc8a79e22244016c29ed0d1a3ad9f1db847a31a304d66a61b43d3f1b82e56c. Chain 2 (Bitcoin): anchored in block 960125 (2026-07-29T15:38:18Z), 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/CZA162400070.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x89a1c7d5913c3608bf1e12aa04498cea30d6b68fa9829de69c159fa4df15bc7e. Chain 2 (Bitcoin): anchored in block 960334 (2026-07-31T02:19:15Z), 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/CZA162400071.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xeb7b7f1ce7e49a0c9682219ded9573f1208e7eceaaf13c46089949f3028f1c2a. Chain 2 (Bitcoin): anchored in block 960368 (2026-07-31T08:26:41Z), 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/CZA162400073.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1f9d06556a01046ca32584eb8a5900785200269bc63cedd920a0357dde0b8177. Chain 2 (Bitcoin): anchored in block 960459 (2026-07-31T20:22:46Z), 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/CZA162400075.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x987206d236c9778af2040eaf2b9901ad9e39cc5fee876ab4db5d4971173afa0a. Chain 2 (Bitcoin): anchored in block 960348 (2026-07-31T05:17:02Z), 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/CZA162400076.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x49a8edcedf99ee65a513c50533bef423f91ed0e145cc147b554d57fb97ad4c1b. Chain 2 (Bitcoin): anchored in block 960348 (2026-07-31T05:17:02Z), 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/CZA162400077.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbe92f4904f6aa42e4875ea1ebbd76ca0197cc3d821becfe65c2159f4c65455fe. Chain 2 (Bitcoin): anchored in block 960459 (2026-07-31T20:22:46Z), 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/CZA162400078.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe2b4cbca328d4f6a20caa9d5696128126e4392edbaeb7ec68a4557ac990c737b. Chain 2 (Bitcoin): anchored in block 960348 (2026-07-31T05:17:02Z), 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/CZA162400079.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe5286a1bcebc6262f4511836c073faaf6a02293eae8a977507027396a22aa346. 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/CZB871202002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9db47005a913a8306a01ea613bd22defb8b0fd26097de00b4c3ef3a1b375e770. 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/CZB871202012.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6798b3fcaa8f56732e160956aa84b499e7e2485e78d6423fb77a23621a2821ba. Chain 2 (Bitcoin): anchored in block 960368 (2026-07-31T08:26:41Z), 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/CZB871202001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x68ec74c7d2a7cfee7f9bad77153406b86d05c5239f4fad059fbae4d0dbeba310. Chain 2 (Bitcoin): anchored in block 960459 (2026-07-31T20:22:46Z), 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/CZB871202004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x022af14cfaed314114071e5eab93513544c896865522262357d27ad5128328bc. Chain 2 (Bitcoin): anchored in block 960410 (2026-07-31T13:50:38Z), 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/CZB871202005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0b8341e5693f34c604ef5544b7a727078b773deddfcf76a813993ceff9c91a4f. Chain 2 (Bitcoin): anchored in block 960397 (2026-07-31T12:24:41Z), 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/CZB871202006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5350ea2001c7e6dbda9a2e0390723126d883211e5b3a648c59acaf746d4be265. Chain 2 (Bitcoin): anchored in block 960376 (2026-07-31T09:09:19Z), 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/CZB871202007.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x608c30dcaec0b64cfeb156e90f8fa4a412f00e50bc5c621cff254f34aa01852b. Chain 2 (Bitcoin): anchored in block 960348 (2026-07-31T05:17:02Z), 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/CZB871202008.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdaeb126a6df9e4369b2641f0e5a787905b3682aea6e18d437f9795d4d0960915. Chain 2 (Bitcoin): anchored in block 960418 (2026-07-31T15:20:15Z), 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/CZB871202010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa4765b5ee9e69d8a592631ce0e77d2616e08414965020bbed59256b5f87815e9. 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/CZB871202011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc1e351baaf902a91126aca5acd736aa907f5e2b083d3e64b9183c109f26d2acf. Chain 2 (Bitcoin): anchored in block 960337 (2026-07-31T02:51:48Z), 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/CZB871202013.