Hudba Praha was a Czech rock band formed in 1984 by Michal Ambrož, after his previous band, Jasná Páka, was banned by the Communist government of Czechoslovakia. The group was active until 2015, with
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 0xa04ced1bf5cface8b58071b44df6acfee94f17b9af5f767731f7c898e704c75c. 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/ba697d28-3d43-43ad-add5-69dde225b99c.json and https://artists.proofprofile.net/proofs/artist/ba697d28-3d43-43ad-add5-69dde225b99c.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
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 0x4af1f9efd208ceb45cce749ac7c07b3d79252da2d08117dc3ef918604b678c12. Chain 2 (Bitcoin): anchored in block 958480 (2026-07-18T02:58:58Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA239300157 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5dfe5c7f988b0baba5eb71c1030edbb064b571853735816d2059e624fc39b441. Chain 2 (Bitcoin): anchored in block 958920 (2026-07-20T18:14:22Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA231201097 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6205a1fe6a39770a429524fa802ccfbf91d8376a8be00bd5b1150758622fe01a. Chain 2 (Bitcoin): anchored in block 956639 (2026-07-04T11:19:20Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA231201098 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5db24bfbcaedf534e59c2182ecf6a2d4220e99615116d2cbfc58fa3a780bc009. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA231201099 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3623be1ad05c88fbac905d7f2cc2d381a00cd0d305fb8049d19d592667376fa9. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA231201105 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4f8203606f07c1c44a7d416cf161463cd429eec57eabb696eda4a7678f892e8c. Chain 2 (Bitcoin): anchored in block 959043 (2026-07-21T18:40:26Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA231201108 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6f23ab5e6eec3565939fa3cd6ae0077ef0ef12caf51ea989fc6b108cbd34e4da. Chain 2 (Bitcoin): anchored in block 958942 (2026-07-21T00:24:07Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA231201110 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x23db960a1aa68eee0006934881a5ddf3f5e8299eecff2c03b050129eafcbfd08. Chain 2 (Bitcoin): anchored in block 958340 (2026-07-17T00:53:26Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZD681000025 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x92b57a1402bd2c269afb9399e6440231cb4f30900ecc342a29298f21c74f7754. Chain 2 (Bitcoin): anchored in block 956856 (2026-07-06T01:25:57Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZD681300014 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8c9804db4d488e06a9064ce789605e04dfee642bdee99f1f9fa25c0e4f2b4996. Chain 2 (Bitcoin): anchored in block 959037 (2026-07-21T16:59:47Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA160300940 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd13bd7319af2bafabf9541ef1680b28106f8c848e6f4d35076a669b9f32e7311. Chain 2 (Bitcoin): anchored in block 958194 (2026-07-15T20:32:27Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA160300943 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3dbde718aca501350aceba23db597d75af5ce739176987d024162e5ba960aad5. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZD681000024 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x81da36eb24942b8a57fa963f0bbcf081cefd30361a4df865354d45b673e51d25. Chain 2 (Bitcoin): anchored in block 958329 (2026-07-16T21:48:38Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA231900083 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xee80ee98e86277e1cde1d4e16d832b69c60914cc13512c2a7e6bd7c7830f9c3f. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA231900084 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa21d35f00a3db43e5b4fa21462cc028be5255e36cc6ea3a8341e18feef0715e8. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA231900085 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2d909d37b6ab5f8b3fc7e28582b59c2882330126c63778b2dcf4ef6f76bef764. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA231900086 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2c8d5c218b2b9d41e9991059e6f672d72da9b28b4bacf889ce3135eae1bb0525. Chain 2 (Bitcoin): anchored in block 958761 (2026-07-19T17:49:48Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA231900089 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6b66f527c63d8c0007acd752e49cd24986ae77e278c2250cfd28f436751b6e6f. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA168878996 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf05a42ec2a5a64e49d3d4618a7449e4dc7bdb6383452d8318713e46ba2598f73. Chain 2 (Bitcoin): anchored in block 958918 (2026-07-20T17:58:04Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA169500333 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x38c5abd49c8b12ee3bdc159c6f938b50b16f6b428b3f61f9461cfc401b8de822. Chain 2 (Bitcoin): anchored in block 959100 (2026-07-22T05:29:55Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA169500334 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbf3e293e718994fb7ac1fff0da23e34a20a0f8e64b316100a550f5b3a3c4ad25. Chain 2 (Bitcoin): anchored in block 959123 (2026-07-22T11:35:32Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA169500335 — a six-check JSON result.