Petr Ulrych (born 21 February 1944) is a Czech musician as well as film and theatre composer. He is the brother of Hana Ulrychová, with whom he leads the folk band Javory and its rock-oriented cousin,
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 0x0e8a43858fbbdda73eb6401dbc34238fa57e2efda0d25a9aaef648972b8c8a3c. 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/32457e92-3fcd-41f5-a39a-ac06f9b20b12.json and https://artists.proofprofile.net/proofs/artist/32457e92-3fcd-41f5-a39a-ac06f9b20b12.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 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 0x26894605066511502b20acce7f8b33ae70e29cb0c2a641410be2a70bef0e59da. Chain 2 (Bitcoin): anchored in block 960321 (2026-07-30T22:27:30Z), 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/CZA167500539.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa02d8b6e473d4b55dd0b9f39146b012ff6563dd6adb62d82471d99ce0cae1f5f. 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/CZA167200484.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x632523a341e3f95268f4a8ca0a093b3f4f7734155b5e89cdcd5eb77ff3d88b36. 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/CZA167200486.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x082035f0b7973842a1d9755cfef5b09614f93f179d175a8437d78aa71f735a9d. 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/CZA167200476.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcbcc15496f2673f4931b6c705b89b3f1af046251b34851bd61505c7cd47e73d5. Chain 2 (Bitcoin): anchored in block 960229 (2026-07-30T08:30:10Z), 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/CZA167200477.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe8ce1a53b8d598ac0f99abb56573941ab808c6694d3db2636823a72f5e9d087c. 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/CZA120202005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x422b91f279bf0ce75c6991db6b6967c4d213871be16b49724d932376e51f68ae. Chain 2 (Bitcoin): anchored in block 960485 (2026-08-01T00:10:46Z), 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/CZA120202006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x15248ebeb6f5887d063324b2cf9d1999860d998a3221aed176095fd10184bfbf. Chain 2 (Bitcoin): anchored in block 960513 (2026-08-01T04:52:22Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZA120202007.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc96337fc0e3dfd8bc3a544f6b82aae5d07ba12b8a29d38b5ca668ff49177f543. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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/CZA120202016.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x23d09a117bc70e4bb8abc1b76440dbda64b5b44ffe30ce2d695f764b18e708b8. Chain 2 (Bitcoin): anchored in block 960302 (2026-07-30T20:09:33Z), 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/CZUM70600010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7ade652493d1fa178e384e738aa5663c5ba2467ac05abcbfad28d9321d1b9438. 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/CZA166900374.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x20fd364ecfd70917ac15170fe59792c4b8b5e952bb9f5de05b4e342aa473f749. Chain 2 (Bitcoin): anchored in block 960240 (2026-07-30T09:57:33Z), 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/CZA169000310.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6f44a322c13bbd4e404c6b6aacf7d62533351089debadc2bca05d4e7f95bc243. Chain 2 (Bitcoin): anchored in block 960300 (2026-07-30T19:42:40Z), 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/CZA167200475.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x280a12cf745cd5dfd2132b968a5d001e5ee3d00aff8690c8981aedaac6848b34. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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/CZA167900404.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x38510182dfe323b6a73f21bf75b9c863d03eb5c9c3a344f2e2c05b2600bea0c2. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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/CZA167900411.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9e204668abc1e1bbbf662141e882142d353f5be18a0988f38a3d9e782f2ab5cd. 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/CZA167900417.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd423b52244973e874954204bbd9f80576020345e043b152ffef4a2244a69f4f1. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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/CZD701166311.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x213b65c6f8332ed58972610929a416fdc6aa81d4148c73d1566e44d0298c22d0. 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/CZD701166317.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x78892073693e1bd1e1bf628ee14a8b5094d997a7ba4016b645f4f47de765c813. Chain 2 (Bitcoin): anchored in block 960362 (2026-07-31T06:58:00Z), 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/CZD701268318.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x87258020e2a78e14c9cfd9abe8d8ff23128f5232f331a6b5265f85e5687c32bb. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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/CZA752259527.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7ade652493d1fa178e384e738aa5663c5ba2467ac05abcbfad28d9321d1b9438. Chain 2 (Bitcoin): anchored in block 957046 (2026-07-07T14:04:01Z), 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/CZA166900374.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8b6c318652034cbc79d0566a9cf3bbcd6c4fd3d5a38658e60ef5bc8740a9a8d9. 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/CZA169000313.