thumb|220px|alt=Image of Dolf Jansen|Dolf Jansen in 2008 Dolf Jansen (born 25 June 1963 in Amsterdam) is a Dutch comedian, host of the Radio 2 programme Spijkers met Koppen and an active Marathon runn
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 0x7ea5665421b5e072b4f9bc459a1f472a368f4666b5af4b159e2abe91bc39f0a9. 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/38b46d5c-f975-4ea2-ab4f-3a53d9d4ba21.json and https://artists.proofprofile.net/proofs/artist/38b46d5c-f975-4ea2-ab4f-3a53d9d4ba21.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 0x5144301d74fd7fa9847c4d63551089a41d0083ecb636ee72ff6f8dc2fbd4f1fa. 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/NLD321200429.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x06f38e797fe8a0b601b85dc82d64f8120c82d7163ae55fd9b7409d1f65f4822d. Chain 2 (Bitcoin): anchored in block 958377 (2026-07-17T06:48:00Z), 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/NLD321200430.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0e208b4dec519c960ddd2b6a410b95faedcca1d68df42ceffcc74d470d77afeb. 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/NLD321300502.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x710812499d00f98262f97dbece7053c4512295e78bef92e0db6ecac54064bd24. Chain 2 (Bitcoin): anchored in block 958335 (2026-07-16T22:37:47Z), 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/NLD321300504.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xece3743f97af8b320ce50eb70aed90e9eaa57de1c947045676b66603880fbc47. Chain 2 (Bitcoin): anchored in block 958430 (2026-07-17T15:33:28Z), 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/NLD321300505.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1d85297d3d9dec7ddcda6d70fbfbeec14802563617cdc4fc2f4c0e71998ace2f. Chain 2 (Bitcoin): anchored in block 958383 (2026-07-17T08:20:01Z), 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/NLD321300506.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4a9c510e98f9a80649490fa8ff8298a14a334e977a9d6b813f5bf74b60688dbf. 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/NLD321300507.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2e627933e697807557514b406f3075983662c9bd5e6baa5e82bf67e66db83339. 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/NLD321300508.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2a56a23256d07c95fe057fc80767a51bd7a2a62f27f4934eb44967d30d84a679. 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/NLD321300509.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x81d930d076cf6ab5a685c220bb59e07bce695477035534d0abde45f6dccacd2c. 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/NLD321300511.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb4daa0144451517bf6ad86d04d4b29288f74486f07ed09f2d163b3f01cbbb212. 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/NLD321300512.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xef8765c3f51d8a54ce98e343661fee9b8fe0fbc281a5e83e07c2d0a865eb33c2. 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/NLD321300513.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf8f33306f930999bb02fa302a91440166b9d7848d1e57ebc05980a8c574b2af1. Chain 2 (Bitcoin): anchored in block 958461 (2026-07-17T23:18:11Z), 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/NLD321300514.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdcf5ef407ac315f66209451bd3c9119d386455ff8c68f5ec415ce79097b52518. Chain 2 (Bitcoin): anchored in block 958544 (2026-07-18T12:14:37Z), 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/NLD321300521.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa5544ff4fbc8af1db5733ade1f04358aef501e68ae1aef41dc15f3e10a389ea8. Chain 2 (Bitcoin): anchored in block 956476 (2026-07-03T09:04:44Z), 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/NLD321300522.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xeb2b9cb47d001d15cc5d4005e5f54be0535d8237c438d816e1e3430a54e7c627. 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/NLD321300532.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbe88768cdf424816c1ea41a019117713c56b6b3c1d65d41c19b93e61bf728e0d. Chain 2 (Bitcoin): anchored in block 958544 (2026-07-18T12:14:37Z), 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/NLD321200439.