Joost () was an Internet TV service, created by Niklas Zennström and Janus Friis (founders of Skype and Kazaa). During 2007–2008 Joost used peer-to-peer TV (P2PTV) technology to distribute content to
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 0xc6cbff001c173f7ba192666bc6d53b6367f1d128ba35e1d99180a011eda76b34. 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/688e33cb-ee81-4446-bed9-1939ed0b59c9.json and https://artists.proofprofile.net/proofs/artist/688e33cb-ee81-4446-bed9-1939ed0b59c9.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 0x99421d2fd4e61d7ca93ac0f92b9e02433185440c5e00212425130182cfb59693. 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/NL4TG2400001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2a48de2af7802bdd6004b3ac15c3b2e5787462b2116e76a0376cb29af7e83ae2. 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/NL4TG2400011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc4bdddbd488f92e9afaf0695ba870c62388dfdf38efbd3d02a35e986fae69bea. 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/FR10S2442657.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd13816107146b2c0aba6ca5804ee87955b231b5c5a5fc7e00ad4c30d7fd8d3bb. 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/TCADP1837539.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf5fb6c16e47b4ad5ff1b0bf53068d8e7e48012a022cb2c7ea7a9abb0b2266ac8. 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/QZES81829589.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc329244afb487e9fb75c9b68fd427dae8eeeb6e5fca1db74e50cf74e48cb5651. 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/NLC242100140.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2240052fabaa9834ec1a350cb2468188280b259039ab522fca47c627e8a1122e. 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/NL1MC2100001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf5357ff73493e095a2a34958975dc6b95c8a76f6d5905ab969b74955101259f0. 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/NL1MC2100002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5702e49bc573d8f3d6d9f8343efdd79258373e9fdb8e90461b91c77baf1348f1. 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/NL1MC2100003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3845a57fe302c468e3dce83867dcf2ec878a1a1d48e3fc98c10b64440a8def49. 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/NL1MC2100004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcbdc4927d60a56c198c3447c1b6684d93fcf8a6eb1ee2160212e238c720ad574. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/NL1MC2100006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6f869387926d88848c09c8629c5106906f9a05c175659bbcc7c3a97add45ec5a. 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/NL1MC2100007.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd9609df6aa6ff56211ccb05e91607e59a22eec4080cb2a38694e952fba5e41dc. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/NL1MC2100008.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaa8855807649269ac51f3c96e2ba38430774ab82d647f5c8c7b52116e92483fb. 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/QZFZ22139752.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6245d253c7460929675685b308eb43265457e2592afe3213e53891fdd37a0dd8. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/NL1MC2100011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1d760507d23552b3ed78e18c54e9b5fff0b0c1abe6f2f42ab41e88b6ad8359de. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/NL1MC2100014.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa3f240ce481e96fe73fc148a36e43ee02f424c92bf316e9495c1bb95bcb88462. 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/NL1MC2100015.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x89a7cfa33ee4fe18be9313d56bf5e2219b2e8105ee2fc27f81ff1c528cc61c02. 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/QZHN71977134.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x195b52dd6d98a84d74e00643dec48d158e02b56089dd499451e84da32628102d. 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/QZHN81962730.