Sam Prekop (born October 18, 1964) is an American musician in the band The Sea and Cake. He also has released seven solo albums. Early life Prekop was born in London, but grew up in Chicago. He studi
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 0x8b00fcbdf8832e6af1b8ed1b32cf4008d041656d6131a3c9896d47245f323867. Chain 2 (Bitcoin): anchored in block 953408 (2026-06-12T19:28:13Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ac66a5fd-7a29-4428-9a09-9a01158c00cd.json and https://artists.proofprofile.net/proofs/artist/ac66a5fd-7a29-4428-9a09-9a01158c00cd.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 0xb20928d7818673dd990b69c451a2ef7c9c2b8dc432da703402fe3de9b6389cdc. 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/USTJ20306105.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3a756f086a81533f5c9f95ec1863fb8ea9e6c6df9bf4fe9d52a746c2f2d5f90a. Chain 2 (Bitcoin): anchored in block 958122 (2026-07-15T08:02:29Z), 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/USTJ20306106.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd40a259ac63d248b823f51cc6ae3f65efba1a615856cf5d80fadda84bcf3274a. Chain 2 (Bitcoin): anchored in block 957863 (2026-07-13T14:41:15Z), 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/USTJ20306108.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4dac0f5e3cc81fa4d694aee12cc5f8e2c8dbefbd5a54b1602c5d6da55c284b76. Chain 2 (Bitcoin): anchored in block 956476 (2026-07-03T09:04:44Z), 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/USTJ20306109.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf8a7a8333e6dc6db8880080c2afbbd8fe7f8ca8e4b1f72716024b7ae2b01fc2e. Chain 2 (Bitcoin): anchored in block 957801 (2026-07-13T04:17:08Z), 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/USTJ20514602.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0907f09755f146200a8820c4a8a926ce59f502b04e3a2fc1c4e8558c4bb8a91c. Chain 2 (Bitcoin): anchored in block 958908 (2026-07-20T18:41:07Z), 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/USTJ20514603.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x74db4d103922c0cf74349bb8f486d2a37245d916acaf5997888ad70cbff9af72. Chain 2 (Bitcoin): anchored in block 958935 (2026-07-20T22:08:19Z), 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/USTJ20514604.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8237b6652ff051742e33422f06d07b5e02c20c57b5bd36bebf757153829a3383. Chain 2 (Bitcoin): anchored in block 957863 (2026-07-13T14:41:15Z), 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/USTJ20514605.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfbccd1f196aff85c767b55b713496f699d54f23861b1569d42d4e0abb1521be7. Chain 2 (Bitcoin): anchored in block 958996 (2026-07-21T13:28:35Z), 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/USTJ20514606.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x975d35b49a066fd66c303f564e6cef33aa95dab49de6e951d7e1558462a5e546. Chain 2 (Bitcoin): anchored in block 956474 (2026-07-03T08:56:35Z), 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/USTJ20514608.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x698acdef95a6d57da8f8bb5263af78889cb8c18698a189d6a1ab3db0d6369f92. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), 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/USTJ20514610.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2fc51c2f2a11f3f0d2ad789e3c97ba3cc951dc3cf9b330b3bca29d158bdb287c. Chain 2 (Bitcoin): anchored in block 958448 (2026-07-17T19:49:21Z), 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/DEX261900980.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5a3b86fdb18dcb776a289ab6633f69b939dac740f07340ba40e210d1ccb3d4ba. Chain 2 (Bitcoin): anchored in block 958346 (2026-07-17T04:00:02Z), 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/USTJ22052401.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9cea3952ee5e2cee2f0ff3daed5b864edecafa2c92d4e1bdf0e611e2e6ff35d2. Chain 2 (Bitcoin): anchored in block 958996 (2026-07-21T13:39:19Z), 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/USTJ22257802.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfd1d306f8704f5e5c5f88a945dc6efeb93ba5d84fe4814e6dba7f7774045bc5e. Chain 2 (Bitcoin): anchored in block 958846 (2026-07-20T10:58:49Z), 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/USTJ22257803.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x755b9568143adc53286cf6d39f240f170bbc6129d83f258bd991e75fc673b5e4. 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/USTJ22564001.
For the Birds: The Birdsong Project, Vol. II
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa4cd7c377d28129666335a84b7c055ee25fa588f6e39d9002c2ead9d80c91b6c. 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/QM6MZ2220107.
Sprout (The Soundtrack From The Surf Movie)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa5034fc56989af050496e5f3244e5606d228b13c175a8df27f55c336a14f819e. 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/USTJ20306103.
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