thumb|Image of Imca Marina Hendrikje Imca Bijl (born 13 May 1941 in Zuidbroek), known as Imca Marina, is a Dutch pop singer and writer. Biography Bijl, born the daughter of an electrical engineer,
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 0xaa36095adb4502b6fe24559b425f0027be5db4ef4825b144d26c5ee2a1d918bf. 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/01fd3a9c-f783-47f7-acdc-b5ae3d3cb12c.json and https://artists.proofprofile.net/proofs/artist/01fd3a9c-f783-47f7-acdc-b5ae3d3cb12c.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 0x8a2385587772c1a4f3c351f689cf101b235ede182cf7ec5dab7a946442e5acdc. 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/NLA271300084.
Zingt Groningse Liedjes (Remastered 2022)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbef68cb6cc109c893dbc4730768bd9ec389b74adfcb859488ba94ae273e023fa. Chain 2 (Bitcoin): anchored in block 957587 (2026-07-11T16:48:26Z), 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/NLA240100631.
`t is zon heerlijke dag Orkestband / Karaoke
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x35bbd9e4cf367d9db623fe6f5dc5f04d5140bae8c2f988012fad8713f716a4c6. 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/NLQG42000237.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x428410e50a7ad46279479c8ddd1684724a4aab620410a75f7cbdc3014efcbff3. 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/NLA270900379.
Vino (Waar Blijft De Wijn) - Remastered 2022
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x408e92dad2b520b34c597c610ee7e633c4b77aa9a59d73de1fbbdb9cc7c467b1. Chain 2 (Bitcoin): anchored in block 957583 (2026-07-11T15:53:17Z), 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/NLUM72201346.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x193aa2cfcda0962e60837bd90f437a342bf002364575deee4e28adf35e2575ce. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), 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/NLA277200099.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb105a130796566733c86fd1824bbf102d33ee7c706ab3635d3b00ff62affb7ee. 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/NLQG42000264.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x088577b00338f57a6ca0a330dd9369b4ba285e505b0ffce2685d93e26c8873a6. Chain 2 (Bitcoin): anchored in block 960264 (2026-07-30T14:36:16Z), 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/NLD450700010.
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