Maarten van Roozendaal (2 May 1962 – 1 July 2013) was a Dutch singer, comedian and songwriter. He recorded "I'm So Curious", and variously worked with Paul de Munnik, Willem Ennes, Egon Kracht, Marcel
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 0xa7df6b0baf2ae4d7dbf0572072e19f972f3d256de27f470e915ee4682ae897dd. 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/f792fc8d-d10e-4e39-beb4-9e0a42babc0b.json and https://artists.proofprofile.net/proofs/artist/f792fc8d-d10e-4e39-beb4-9e0a42babc0b.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 0x09fd862111e72135a0d5885291c731c2991facc70e79628b89be3f7dd0ffa935. Chain 2 (Bitcoin): anchored in block 958058 (2026-07-14T20:20:34Z), 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/NLC289500162.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa280db7a62ec65dd8ad373e8c0815f5e83770b268afc431f1ef874fdb8030820. Chain 2 (Bitcoin): anchored in block 958975 (2026-07-21T06:12:52Z), 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/NLC289500173.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4aaa197ac5b103c3092eee469da3888ab1e1faa1276d83ac9aa2197a65038890. Chain 2 (Bitcoin): anchored in block 959052 (2026-07-21T22:36:20Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLC289700189.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x639d2f82032f784a834b1157000d958b577b68935a6b568449ecb27187632749. Chain 2 (Bitcoin): anchored in block 958121 (2026-07-15T08:02:12Z), 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/NLC289700206.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9f7cfdcbab0ac9b03004e18c9d7f5e07d3ac0da090f21a8600b8eaabadfaecfc. 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/NLC280100168.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x37c3450d6c77b63ed1857d933b4c9627d36882a44e3dcda4f23e74695bb75559. 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/USHM21374338.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x757f0a5601469f21f0b1dafb017a60fa6647f1d3ce02687b62d93bd1966fd076. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USHM21374342.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x892b68c348253f971ab49f876bbc3ac84c8ddb298b97aa541d9db2f4e4c5f488. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLK190600002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2a230d6393b3e1ba842e49faeefa57b95583cab2c43393ec41eeedd017a18e79. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLK190600005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x997be8c7702e7d012821c5038a40660f4d1cd14d9d58b685806639cd7aedaad8. Chain 2 (Bitcoin): anchored in block 958153 (2026-07-15T14:54:49Z), 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/NLK190600012.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcce1a5010311a002d45b73e3f821bb54379ae442826af3a08195b504451884cc. Chain 2 (Bitcoin): anchored in block 958060 (2026-07-14T20:39:42Z), 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/NLK191200006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x16a2fce6eb540eeb17971f5dd2030de9c9b8dabb83c7b78c6d7feabe63287dc6. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLK190800009.