Petr Hapka (13 May 1944 – 25 November 2014) was a Czech composer, one of the most significant composers of Czech film music scores. He is known for his collaborations with the lyricist Michal Horáček.
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 0x03e025f9e3f33245294c59147718b02f36749fa0a3aa82621aef416d5a92535e. 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/2aa95948-eba3-400b-aa1f-cc5001102ae0.json and https://artists.proofprofile.net/proofs/artist/2aa95948-eba3-400b-aa1f-cc5001102ae0.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 0x7eac659c21df79459cb25c29cc04a0a5c150a970ad3a48eafc295cf1bc93d251. 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/CZA110306076.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x034554ea50bdd07f63cde8024225b735f4dbd6001dc8484a395881350164805d. 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/CZA110306075.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x59b1e52ab0af5c23514e92122fccfac99f669a43eccbedc66c5265e4b53e94b7. 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/CZA110210001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd94896ad38f3b4c21c53087b81937a045f16baa26d2fe54ffa258e396dc6355c. 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/CZA110306073.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xea121992c692116949a574194142bdd21dc46a3cdf680cbaffba3787f16f0f4d. 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/CZA110306072.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfcc57c6d332465914b0a05cbe3793f76533a3aa94cbb0fdbf3e4d9ecb286a585. 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/CZA110306077.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd7f7a1ab6cf007a7846e4e07f45bd73125270ba8d044c233752bf4a2209b3f30. 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/CZA110306074.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x332760dd3b5fa1ff2ed56578496e430f0fc6c9cb3c2b6bb63b0d6e03a3775850. Chain 2 (Bitcoin): anchored in block 954130 (2026-06-17T19:07:14Z), 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/CZA110306078.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x65b603a33f48b094e8f783d4421fd9b3cc23b2324dcb48c887d179e60f1d8baa. 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/CZA110306071.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb7739e4399cf340b366f7a3a59a4b7206ede502acef868a738ede196a151cc30. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/CZA110102002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcef41ab0cfdfe53cd5032d560be13e60f84428baf32655bdfa9f334b2b68e8cf. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/CZA110102004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x91fe3a45b342e8365b9554899c685e74d04f5603803fc478dcc7615107654f4f. Chain 2 (Bitcoin): anchored in block 956551 (2026-07-03T21:18:05Z), 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/CZA110102007.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd1242101f2687f7aa726845ad747669bbb23233ae0eb9b98e3eaca028fa822d4. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/CZA110102008.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6c342741c25bc5111ee679a4a854067c7603863cdadfb6e369b553727b85dcc9. Chain 2 (Bitcoin): anchored in block 958316 (2026-07-16T21:57:12Z), 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/CZA110102009.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xede5e308cd7efe821abba9f90d7f75dc017ece3c228ee3fa101b822bb7766c52. Chain 2 (Bitcoin): anchored in block 958901 (2026-07-20T16:37:25Z), 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/CZA110102010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4c00d603d7749b8bb1ded8fdefde7057dd4b9b3b9519078ebbd317a8a91df641. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/CZUM70600155.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc8d9356a67830e4225c3741c93fdb0f1998cf85b08928669ea9aa408ae9640ce. Chain 2 (Bitcoin): anchored in block 956485 (2026-07-03T10:53:04Z), 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/CZUM70600160.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcb9285122103b3cb54229bbaa9256974bb08768be552a7f72a2b608b5bcba648. Chain 2 (Bitcoin): anchored in block 958303 (2026-07-16T16:39:24Z), 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/CZA210901008.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0953b4c81a2cad63d254f5b86798a2c5b6ede39f8581a1c327b63f6f5c2bd755. Chain 2 (Bitcoin): anchored in block 956500 (2026-07-03T13:55:21Z), 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/CZA210901011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7d6da932af74a810846d2ab7d2f573eeb628ad7a77c3c72a27192d2b46c8cd08. Chain 2 (Bitcoin): anchored in block 956656 (2026-07-04T14:03:39Z), 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/CZA210901013.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x021436acb32c5cc985b548567bd8f56ee9a04d77dea16ec5e1efb19224a76ffb. Chain 2 (Bitcoin): anchored in block 957891 (2026-07-13T18:21:04Z), 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/CZA210901009.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3613b1ce561b0543005ff4b306b329994c1d2177a2691a28f921c6392852d810. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), 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/CZA210901017.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd1e725f5e13cab9138fefd05f239e669c9c33006b1fed44fc3a417f40dff4579. Chain 2 (Bitcoin): anchored in block 958303 (2026-07-16T16:39:24Z), 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/CZA210901010.
Benefice cernych koni - Best Of 1987-2010
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb6ce7cb15f954eb824f978fbc0c4f92134059d175f21aed0366d61fd81466331. Chain 2 (Bitcoin): anchored in block 958430 (2026-07-17T15:33:28Z), 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/CZA167700135.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7e87f1d650fd38f287f493943dc2366ac063dcede711ae7c17115e0f1b742cea. Chain 2 (Bitcoin): anchored in block 958377 (2026-07-17T06:48:00Z), 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/CZA166400125.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8c999c4635e916cc5476f3ac363188868bc60bb38a66c6f446f0f8f0d6633f9f. Chain 2 (Bitcoin): anchored in block 956826 (2026-07-05T19:27:56Z), 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/CZA166600133.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x59b1e52ab0af5c23514e92122fccfac99f669a43eccbedc66c5265e4b53e94b7. Chain 2 (Bitcoin): anchored in block 956891 (2026-07-06T07:16:32Z), 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/CZA110210001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe5cb6443ba8bbe13570ce9e98067420e52851939c544f52ec7d15c22f3d48b54. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), 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/CZA110102003.
Nejvýznamnější Skladatelé České Populární Hudby Petr Hapka, Vol. 3 (1980-2003)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcf87b89a5ee504e3e0764e2a667f4445072257d1ae1fd5556a1757329c0be12c. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/CZA168600186.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x55651656ebfd7ad6493f55a5a297cb5614d4096e01c1cec20d3d68dc74452fe8. Chain 2 (Bitcoin): anchored in block 956349 (2026-07-02T11:34:59Z), 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/CZA168800574.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf52ef9f4d25f18dfcc70a05fa477756a56b6fd4d1142aca0d90133306e8fba54. 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/CZA161003359.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb4d53965dd37ae8d1d83ac99d2bd52b184bf2b5de3fa85fe220838b57a63a7b6. 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/CZA110210010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x55651656ebfd7ad6493f55a5a297cb5614d4096e01c1cec20d3d68dc74452fe8. Chain 2 (Bitcoin): anchored in block 954130 (2026-06-17T19:07:14Z), 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/CZA168800574.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1061ba7417c58650ae3c9d6f5ae2ff73de12e9d2c23b3f3fd6287def1aaadc08. 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/CZA168800085.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb4d53965dd37ae8d1d83ac99d2bd52b184bf2b5de3fa85fe220838b57a63a7b6. Chain 2 (Bitcoin): anchored in block 956349 (2026-07-02T11:34:59Z), 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/CZA110210010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe5cb6443ba8bbe13570ce9e98067420e52851939c544f52ec7d15c22f3d48b54. 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/CZA110102003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x219aec3ce79dee02ab3a25c93e4c877f76654eee8750f068ea5655e8b94569f6. 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/CZA110102001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x598ca3ebd2ebf14588acdb9d99f3a3446d749d222a7c5978165c9ca1fcdf5a89. 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/CZA110102005.