Opgezwolle () was a Dutch rap group consisting of MCs Sticky Steez and Phreako Rico, and beatmaker DJ Dippy Delic. Biography In 2001 Opgezwolle competed in a contest called "De Oogst van Overijssel"
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 0x4c582871c6a39e757c5d87bd55dce99eb692001a628bbffd9dca638aa5a1b8b6. Chain 2 (Bitcoin): anchored in block 953423 (2026-06-12T21:20:00Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/3d1e0de4-6c11-4521-8897-41302a77d9b2.json and https://artists.proofprofile.net/proofs/artist/3d1e0de4-6c11-4521-8897-41302a77d9b2.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 0x3135385490fe8c463348734a206264ada407b2d4a184b65cb65cbb83322d02e6. Chain 2 (Bitcoin): anchored in block 958197 (2026-07-15T23:15:55Z), 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/NLG661400231.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb00c5b07e6133adea8a320ee926add865e6b441bbb808079f84c5428b15d0377. 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/NLG661400233.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3e7c2117c2b4386ca95019569640829e23ff9d41398da480eb85b63ea6903525. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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/NLG661400234.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb79c2535ee4c1fb5c1dec9891df3f164f4c1cd404cb6d4208eb854538a524229. Chain 2 (Bitcoin): anchored in block 958319 (2026-07-17T02:10:51Z), 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/NLG661400236.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x94df40d3b180ce1725bc48f0551508f836d9a1994d6be696eaec46bd46a636f5. 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/NLG661400237.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc088a130d64f57fe4da820cce2f005a71cb038ecbc8da6ea5584ee8f4b952356. Chain 2 (Bitcoin): anchored in block 956776 (2026-07-05T10:59:37Z), 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/NLG661400238.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaeeafd2df9d78a3036e8e87cb1751eb38614e13cc4bf4a243ec0b96186d65007. Chain 2 (Bitcoin): anchored in block 958234 (2026-07-16T03:46:09Z), 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/NLG660400081.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x95c38ce71226e816145aaaa4e155204a5937591cf55c4994279ade9ee49b901a. Chain 2 (Bitcoin): anchored in block 956422 (2026-07-03T01:01:38Z), 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/NLG660400083.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9c02896cadb52cdd8c88bbab913406b0dfd40b95a281d5cfa5e0e56f94b852c7. Chain 2 (Bitcoin): anchored in block 958319 (2026-07-16T22:11:00Z), 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/NLG660400086.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x69c8928dfc6bc8b136621bdf964266d9ecab9f022960fe3a4ae05c9b30e32bd8. Chain 2 (Bitcoin): anchored in block 958444 (2026-07-17T19:12:23Z), 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/NLG660400088.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6ef3075c47217e485e227d63789c2f3a1bd65a1b8b303558dec247ed32d0cdc7. 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/NLG660400089.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4ff78765d24e924127f5fc2d68b8781117d0d425a991ba21f99aa3fb346d7cbc. 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/NLG660400091.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x05498f7ddf9f99d1c45b87f68648a4a854eccda8544016311c429e65333d695b. 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/NLG660400092.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x64dcabfbd537b02f2234cf54fedec3ec45393ba602d2630ff2818e443ce7fe7c. Chain 2 (Bitcoin): anchored in block 957919 (2026-07-13T23:58:45Z), 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/NLG660400093.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x16b29ea779f52466dbe29fbf7382eed174a56162f9e56c4e1062be245dde0ad0. 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/NLG660400094.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xef03a18726a222414c0266024bb0c9df6a5d37c86f219256ebc5985a7a5145bb. 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/NLGBB0600007.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2a5c72e68067eb517ac97d81ce52396231897a5235f52fbfeb5c9b684ba69f6b. 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/NLGBB0600020.