250px|right|thumb|De Kift in the ACU in Utrecht on March 19, 2006. De Kift is a Dutch musical ensemble that was formed in 1988. Their music might be best classified as fanfare with influences of rock
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 0x5d4553f84e4e226560fb9d445fbf2253d8edbea46027db07bff78b139a5a8d0d. 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/31620b1a-4467-4082-a6d1-280791c6641a.json and https://artists.proofprofile.net/proofs/artist/31620b1a-4467-4082-a6d1-280791c6641a.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 0x4c895e6d6202432c55e1777f8397a52b6b2f286f9e7751ba4c9caf9fc8042134. Chain 2 (Bitcoin): anchored in block 958228 (2026-07-16T02:46:47Z), 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/NLK189900003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa4691093e6b408db74c84366646a391f5c4920f791a4b0901dd71ba8ca138a0e. Chain 2 (Bitcoin): anchored in block 958911 (2026-07-20T16:46:31Z), 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/NLK189900012.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9a5c8fde3188951b9c37ac87ab2901428198d9bde69a4f07398c1ec17a37cb4b. 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/NLK180100001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaddebf0cae4918b78dac50d2225179cc8d054e8a004f364fc1beb8b9aa75ddc4. Chain 2 (Bitcoin): anchored in block 959065 (2026-07-21T22:00:50Z), 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/NLK180100002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3277300796dc799ff7ea70640a93954204319cc868f17ce40888b055456a6d03. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), 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/NLK180100014.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7e8d747b0cf87b7ee713f0587355d375be28db295ff3ca63087f5f7e01182669. Chain 2 (Bitcoin): anchored in block 958300 (2026-07-16T16:14:30Z), 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/NLK180700001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x334244f771e4292e9ac15f2afe99e5c378a4911cede2863937802dafb840f6c2. Chain 2 (Bitcoin): anchored in block 956856 (2026-07-06T01:25:57Z), 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/NLK180800013.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc73ff92a4227ceea35b097acb9d3b532cc6c63e760794f701c9c9f71e3c5a056. Chain 2 (Bitcoin): anchored in block 958761 (2026-07-19T17:49:48Z), 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/NLK180800014.
Jan Douwe Kroeske presents: 2 Meter Sessions #1739 - De Kift
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x07d986f36a2eca969f24074c3f4bca4a9b62063cfb533a4107a0f1299a3ffc8d. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/NLK182400007.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4ef18b3d65e5bf8656cdbc8fa6078fae715119e277cb81bd41d644469c4847e4. Chain 2 (Bitcoin): anchored in block 958538 (2026-07-18T10:30:13Z), 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/NLK182400002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x62c0897f5d0cf699461da804a089e3f72c8f4da9d66a5183f8ff0664e249de2a. 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/NLK182400004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x164b06896ebc2f27e304d7d0e28bc586544564603d350ead154f02f3bc7cf46c. Chain 2 (Bitcoin): anchored in block 958468 (2026-07-18T00:27:51Z), 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/NLK182400003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4809aba04b5f94fb5910f1799cca2ebef9c8e606b8b8d236a1334220455e3265. Chain 2 (Bitcoin): anchored in block 958742 (2026-07-19T14:09:34Z), 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/NLK182400006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaefc243ffa11857092b06e24a9c9f2359915e34c0f80c9e68149ba6eb014de1b. Chain 2 (Bitcoin): anchored in block 959073 (2026-07-21T23:25:37Z), 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/NLK182400009.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x31c0123fd5a19562dc1d1353c10e4481ea19efca76c57c85552d7a3f815d915a. Chain 2 (Bitcoin): anchored in block 958428 (2026-07-17T15:15:14Z), 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/NLK182400013.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x24ff0717a9883c356f66d0970371edbb4a8d6b27a5f8d667b2b83dd36b132c53. Chain 2 (Bitcoin): anchored in block 959015 (2026-07-21T13:52:01Z), 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/NLK182400008.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0a72babfc761b0770c0e01704c8784b4a0ec6da8fa7f2a6147e6f3e6bd0cd120. Chain 2 (Bitcoin): anchored in block 956841 (2026-07-05T22:14:35Z), 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/NLK182400001.