Kaj Erik Persson Hassle (born 26 August 1988) is a Swedish pop singer and songwriter. His career started in 2008 with his first single, "Hurtful", which eventually reached No. 11 in Sweden and peaked
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 0x0abc3a5088a5d442cbf22be2e17b214ea47d2763ee99268efb1be8b76b52ba12. 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/ac946511-2162-48e0-8d9a-d905cba27e87.json and https://artists.proofprofile.net/proofs/artist/ac946511-2162-48e0-8d9a-d905cba27e87.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 0x58506cf91554d1f36f9426dfbc43dcdf56fd98fa1dc52e667ff5a581f92fd597. Chain 2 (Bitcoin): anchored in block 956484 (2026-07-03T10:47:44Z), 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/DKBV70859003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x14cbb9db5d56a7e5c62dace99fcda171cd082e1d2497709fb90fb2454eaec374. Chain 2 (Bitcoin): anchored in block 958876 (2026-07-20T15:00:34Z), 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/DKBV70859002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x570045ba41d84232fcbfee537271999edcd617b77b103d6e8f7a777e46aeffbc. Chain 2 (Bitcoin): anchored in block 956857 (2026-07-06T01:26:17Z), 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/DKBV70859010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4e5bc729459bada09a56c6e8af3a4700e2189fb70250d9d327309e425ddd011d. Chain 2 (Bitcoin): anchored in block 956738 (2026-07-05T04:47:21Z), 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/SEWEE0900202.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9621e88c9ba3dc8e379f4406c0ab296d793e8d10b9e35280f893e556fd2c6d9b. Chain 2 (Bitcoin): anchored in block 958963 (2026-07-21T04:02:02Z), 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/SEWEE0900203.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1b993a46a056cad69a55bb5fa2679fcace342288cc20c3801270965f1cf0da3d. Chain 2 (Bitcoin): anchored in block 956576 (2026-07-04T02:06:47Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/SEWEE0900204.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa564b7792f6cc8d579ff9efd5e7aeadd698cffdb43aa59f883608eafccb6ab83. Chain 2 (Bitcoin): anchored in block 958489 (2026-07-18T04:13:26Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/SEWEE0900209.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x954650a94472d47fa880002e2d76b4b8302b26ebba254d8b0c55c221aceb2933. Chain 2 (Bitcoin): anchored in block 958700 (2026-07-19T08:09:50Z), 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/DKBV71108901.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1db56c83ac9e066d3e8ca8ea7b91761675b9f36fd27c68390c9fe44d8fa72e15. Chain 2 (Bitcoin): anchored in block 958514 (2026-07-18T06:54:37Z), 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/DKBV71018001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb1a5c70ea76e580a97cf9194dd0fc8fcd204f87adc6e99df27a9fc7d0f4a1b7e. Chain 2 (Bitcoin): anchored in block 958169 (2026-07-15T18:53:58Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USRC11301725.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcbce4e1dd94a0196ea46d11cf53a195fed2923cbbbd27534b063adfb7cd62101. Chain 2 (Bitcoin): anchored in block 958733 (2026-07-19T12:51:21Z), 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/USRC11400331.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6983439bc83c6b239bf2be1910daf1cde767f766804e55d90cbf96af18a3e560. Chain 2 (Bitcoin): anchored in block 958601 (2026-07-18T19:27:02Z), 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/USRC11400333.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb687251c0ada20c9dbad39ab99027224b7c8f97373b47898f7aba4f23fc521ad. Chain 2 (Bitcoin): anchored in block 958276 (2026-07-16T12:44:31Z), 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/USRC11500049.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7a196a64083e39052747861d3d857e91e7dbf82509674ebc0213842436f39a66. Chain 2 (Bitcoin): anchored in block 956420 (2026-07-03T00:42:11Z), 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/SEWEE1501402.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x38a8772617f5cf4327ae84db5330cb28e6e4e7c115126843342f5e24174be336. Chain 2 (Bitcoin): anchored in block 958660 (2026-07-19T04:21:53Z), 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/USRC11602930.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xeb0759d2813665966d30a6eb4a9564d621aa1daf5cd6c0ebaa49ea8b5e8d04fb. Chain 2 (Bitcoin): anchored in block 958489 (2026-07-18T04:13:26Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USRC11602410.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x38a8772617f5cf4327ae84db5330cb28e6e4e7c115126843342f5e24174be336. Chain 2 (Bitcoin): anchored in block 959047 (2026-07-21T21:42:05Z), 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/USRC11602930.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1bacd27b60bf092823d876cc28280795d61ded0a8106ce79288caa1bff0a9a2a. Chain 2 (Bitcoin): anchored in block 958706 (2026-07-19T08:50:34Z), 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/USRC11602408.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xeb0759d2813665966d30a6eb4a9564d621aa1daf5cd6c0ebaa49ea8b5e8d04fb. Chain 2 (Bitcoin): anchored in block 958514 (2026-07-18T06:54:37Z), 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/USRC11602410.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x365838cecccd3eb1990e7ee0f5dfffe91a84308c41ddef594affb182557d74bb. Chain 2 (Bitcoin): anchored in block 959026 (2026-07-21T15:38:13Z), 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/USRC11602407.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xeb0759d2813665966d30a6eb4a9564d621aa1daf5cd6c0ebaa49ea8b5e8d04fb. Chain 2 (Bitcoin): anchored in block 958134 (2026-07-15T11:38:35Z), 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/USRC11602410.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9bdadb018a4ba863f403e93139eb5e80ead32e2c8b24f09dc77a075dc33ce8a2. 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/GBUM71404003.
Midnight Serenade (feat. Erik Hassle) - Kungs Remix
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x187a7a68aa0d7db6ceee5d516a7691df81fc75dbaa9ebc291a8270c4201f8691. 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/USUS11600084.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7630ba776faa6b90696aca271ea297c2f16f4fe065e13f16deca5c5ff8eecba0. 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/USUS11500076.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf44774f6fe7f2866594a7d1304403e459faaa859b03dbee580a2a736ad44f56f. 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/SEWEE1300804.
The Ultimate Workout Collection: Keep On Running
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x71d407d78df398b55f4269d29d1354839e77a44a3d050c7baf3e4a7b2ae947aa. Chain 2 (Bitcoin): anchored in block 957061 (2026-07-21T20:53:12Z), 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/GBUM70913539.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcf27aac41850cb7d2ff3daa37edae3a8d69d74fe4bf9630acff4915c51ef9057. 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/BET671000140.