Sietze K. de Vries (born 1973) is a Dutch organist, church musician and academic teacher. In the context of his international concert activities, he became known for his renowned organ improvisations
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 0xd62f644ceb84c380eb59ce83e72cce26c7e91a86ad8690c4d649f0fe3805428d. Chain 2 (Bitcoin): anchored in block 953765 (2026-06-15T08:55:24Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/bbc0996f-ad19-4ebf-a6c9-a42031522fb1.json and https://artists.proofprofile.net/proofs/artist/bbc0996f-ad19-4ebf-a6c9-a42031522fb1.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 0x9b9214ff2fbcd954c660ee48877441bc141d6f6df7258a5464c54e5f89778671. 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/TCAFP2150842.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc7f034439e81035ece7972f20ef08333a2ef356dec745da16c8389f4edaa2bce. 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/TCAFP2150848.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0d62516833ece3413b713d2b5c30a0bbac5cc9d23b697b7c58de494b9cced7fd. 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/TCAFP2150859.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2985ca240298a7cf49f449781d87530b5ceeaa8627aefea4d71b9b1fe66d46f1. 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/TCAFP2150877.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x98188b8c98a0778ac262abf3db1525aa9abbcb58106210ebae614022e753c69f. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/TCAFP2150890.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xde3fc9aaea46c26957061a6f047f2f763bd76451630a6f100dbd1ccd2bf2ea16. 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/TCAFP2150938.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaf78d645cc0857c4154f654a7dd9fb91616d4485e5dc5a50f73795811121a3f0. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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/TCAFP2150944.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1851ad6b490d3d0c2474f0d4da6926641fbf2f78d5b060db89854391c49542ce. 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/TCAFP2150951.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x16358279c8c0cc2ccb9322c748352ef15eb95cc1728a727006620e04c5954b2d. Chain 2 (Bitcoin): anchored in block 957122 (2026-07-08T03:39:04Z), 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/TCAFP2150960.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x80a16b4093b60f7d1b5121e67b69a14faf89d632601dbdd23ea1f75935b79bf5. 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/TCAFP2150965.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x68355da38f99a78fb7c32b3b79b2832afc3e9c47510031c3122de915bf43ae82. 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/TCAFP2150969.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe9056715ba54cff5310d1e4aeed9b70a8640f58862f8a57a7eb4f790af3cc1cf. 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/TCAFP2150970.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x081435760e8ff699b3eb6cb2e44a92c32d90763272f8c1240093b5ab1419c1fa. 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/TCAFP2150976.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8d7f098cbc0e8458a7a75a4aa28d3f8012c7abfd9ec0b31d8a9df46c7e186dfc. 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/TCAFP2150981.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x274c3414dcf539bd41068afe3004813d2679fca32d79e89d01a8596bc5bff1f6. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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/TCAFP2150993.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7b2acbd7cbc24747ef0b30271210825856c6fbdd9cf291bc0e0555bd30721ed6. 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/TCAFP2150996.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9f5e216eb78b008fa2ffd7810f61043d8ae3edbd50062cec34027a58ac4a5594. 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/TCAFP2151002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x81855ee7ed4015e5dc95b677563b730d684cc6223e25c4dde6afd2c40ab0c48d. Chain 2 (Bitcoin): anchored in block 960317 (2026-07-30T21:35:24Z), 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/TCAFP2150807.
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 0x022e252a4efc017d5a66f3256533c556c79b55783d97ae5bd187955c8644df52. Chain 2 (Bitcoin): anchored in block 960276 (2026-07-30T16:01:17Z), 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/TCAFP2150834.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x974b78f3a134999196f887db999ab36c5495bea4c2a78b799c9aaba98d92294e. Chain 2 (Bitcoin): anchored in block 960383 (2026-07-31T09:50:37Z), 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/TCAFP2150856.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf51548a1b874f98c19e62c9c67566c3f9e5a6739ebe7e19d79eef4e696d711cb. Chain 2 (Bitcoin): anchored in block 960321 (2026-07-30T22:27:30Z), 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/TCAFP2150867.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7a71e25f326c6ad9214d2458b148d9c4175679ebacc8ad52f24cea33a6a44e21. Chain 2 (Bitcoin): anchored in block 960370 (2026-07-31T08:38:45Z), 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/TCAFP2150885.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x31350c7d1e7d02d1c5aa4d8fb14e4c32fe079b5e6d5ddb747b63ce4c39e84356. Chain 2 (Bitcoin): anchored in block 960397 (2026-07-31T12:24:41Z), 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/TCAFP2150919.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd6398dcb0917d47d9c6a83e9fc86fa7572a4b6d7a8f10112818481be75e3d148. Chain 2 (Bitcoin): anchored in block 960327 (2026-07-31T00:26:26Z), 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/TCAFP2150922.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbaeb9896be1c805a5150a803540ef004ea1b8e12fa0085658f0bd2e8d27d2d83. Chain 2 (Bitcoin): anchored in block 960397 (2026-07-31T12:24:41Z), 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/TCAFP2150929.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb09894fc6dbb7535317e8ccc8686e9cb13140d9c2027a76def5c14e569330a34. 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/TCAFP2150930.
Ik Wil Mij Gaan Vertroosten - Versus III
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd10d98998a4caab7b7c8eb12106727b71cadbd945ab3c641ea3739f8e3d3373b. Chain 2 (Bitcoin): anchored in block 960429 (2026-07-31T16:07:24Z), 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/TCAFP2150935.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd89a2606bcf4b5e0e48e9b74fab2887c0b59c6a74897d8bd4a0c7501f3394eff. Chain 2 (Bitcoin): anchored in block 960497 (2026-08-01T02:22:04Z), 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/TCAFP2150939.
Ik Wil Mij Gaan Vertroosten - Versus VII
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfb7b03cd0fa1847acabc5c2368cc6e34c6f008b3f41e4041af314613e13ef7f8. Chain 2 (Bitcoin): anchored in block 960435 (2026-07-31T16:33:26Z), 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/TCAFP2150946.
Ik Wil Mij Gaan Vertroosten - Versus VIII
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6de9cf3fc942265680889fc21c24a5a9c1cc79c0953a4e5c6f195845f172944a. Chain 2 (Bitcoin): anchored in block 960500 (2026-08-01T03:13:03Z), 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/TCAFP2150948.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3541f46b04b9e23782632823cb7d871f351ca0110c62c5b1304f2b75b3fbe478. Chain 2 (Bitcoin): anchored in block 960513 (2026-08-01T04:52:22Z), 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/TCAFP2150954.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0dee305f711dba77a123cad7076d2e3812f1a98056b04effb09092a9440ea9cf. Chain 2 (Bitcoin): anchored in block 960509 (2026-08-01T04:30:37Z), 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/TCAFP2150964.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaded60162d73caf6284d3eee8139948659fba6c85f65d8013ef1879ca372a389. Chain 2 (Bitcoin): anchored in block 960503 (2026-08-01T03:41:24Z), 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/TCAFP2150989.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x847fd7e639868220b18684c16d2dff99b0227011fb38cda44f793b5e6c91ad2d. Chain 2 (Bitcoin): anchored in block 960506 (2026-08-01T03:50:58Z), 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/TCAFP2151014.