thumb| Paul van Vliet (The Hague, 10 September 1935 – 25 April 2023) was a Dutch comedian, singer and goodwill ambassador of UNICEF. In 1957, he started his career as a comedian within the student ca
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 0x0aa6b55816f5edc073765cf01bedca1f8026b2529ef7b622c1b8be36e79a3d3f. Chain 2 (Bitcoin): anchored in block 953724 (2026-06-15T01:43:13Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/8d8a1de4-3d02-49ce-bca3-fd08246908cd.json and https://artists.proofprofile.net/proofs/artist/8d8a1de4-3d02-49ce-bca3-fd08246908cd.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 0x21436cdfdc0bbe58f1b8d8f1014cc9c69ea75c3b86923f4c4bf4c51f637012d9. Chain 2 (Bitcoin): anchored in block 958074 (2026-07-14T22:45:25Z), 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/NLD321900195.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2785df133cd362aaee92bd44a6ce5c2c7817c8615bd30089ff0c87b0c32e8572. Chain 2 (Bitcoin): anchored in block 960441 (2026-07-31T17:29:52Z), 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/NLD321900397.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd624cb072b00d629bd4c6009e67fb9433efebeb30dfb5c01d9282b335eca7d50. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/NLD321900399.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd4547c1b9acb963608cac92882a44edd7f90b79d2580298318ede36728284076. Chain 2 (Bitcoin): anchored in block 960456 (2026-07-31T19:53:57Z), 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/NLD321900401.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc6b9acf9f0756413aec00d8ab9ace0167ecbff5515b1a90be7599b79980e5dab. Chain 2 (Bitcoin): anchored in block 960340 (2026-07-31T03:15:04Z), 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/NLD321900402.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x53246d2d75fdb705c0e62299e931af8d040a9818a580e55efc1032b948901228. 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/NLD321900404.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe23e3d8090a15407810c1788ed944ff3aaff19aef8b92ad9fead6eaaecefdddc. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/NLD321900405.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc08eac9a0e3480a579725e8d5bcce05fd987348d00de451e3e6d5faa46b0c414. 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/NLD321900406.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd5179e1e234685ae4833275fdc6e2879036c99ecdba995457704236785ee7061. Chain 2 (Bitcoin): anchored in block 960441 (2026-07-31T17:29:52Z), 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/NLD321900407.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc34aba9ee9611e97728253aabc9979dd5b388520059da7e689e0b11fced01f83. Chain 2 (Bitcoin): anchored in block 960410 (2026-07-31T13:50:38Z), 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/NLD321900408.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2624a38740cfad6dcd1f02d939170b7ab2ccb8f99da66e335f677cc48fc4c272. Chain 2 (Bitcoin): anchored in block 960463 (2026-07-31T20:42:35Z), 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/NLD321900409.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xde621e96d6a58cf2c216bb5d1f603a51e7e9d9dc55b5e6dc6445f08856f6e03a. Chain 2 (Bitcoin): anchored in block 960463 (2026-07-31T20:42:35Z), 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/NLD321900410.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7bad04e5fb661f8f6c486c15f18317de1d6d6e7d9f4432af67fec943e89ba252. 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/NLD321900309.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9b999af969ad1fa1fef2247d30f649b4506d8df2fd11202b8868c8746de354cd. 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/NLD321900310.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4637be342344e2cc9ebe5c64ed2e1e7cba9f767d6beb6797e2854b88f77c802c. Chain 2 (Bitcoin): anchored in block 956822 (2026-07-05T18:48:28Z), 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/NLD321900313.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdba1482e2f187b8f1045efb64b97649adc546f251d927852001d69fb7c5211ea. Chain 2 (Bitcoin): anchored in block 958853 (2026-07-20T09:11:53Z), 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/NLD321900315.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe35e1576017c7b57c43561a076205e7e2336e30edd4239a17aaf35e2fa1195e6. Chain 2 (Bitcoin): anchored in block 956745 (2026-07-05T05:33:35Z), 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/NLD321900320.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb914c9443185ce6efc4e072f3a841d620534e3c47a316192b0329944b94802e3. Chain 2 (Bitcoin): anchored in block 959018 (2026-07-21T14:12:28Z), 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/NLD321900321.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3c3c322f4a011488671bad2daf3a5f81e99c4444bc9f6f398644e83a82ec120b. Chain 2 (Bitcoin): anchored in block 958286 (2026-07-16T12:43:37Z), 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/NLD321900333.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x90c08e270e4b3af9ea6d90f378dc1657354f79677e8b60cb11046be394c5777c. Chain 2 (Bitcoin): anchored in block 959084 (2026-07-22T00:50:00Z), 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/NLD321900257.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf46ad07221ecdb394f9c85551516bb092edcccb5a2fecc19e8a9048d3f59df32. Chain 2 (Bitcoin): anchored in block 956889 (2026-07-06T06:56:49Z), 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/NLD321900274.