thumb|Cor Bakker (2017) Cor Bakker (born 19 August 1961) is a Dutch pianist."Plein concert Almelo again great happening!" Almelos Weekblad. Retrieved 2018-07-03. Bakker was born at Landsmeer. He ro
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 0xe38cf94bb03aa9a2573d720164435500928a321b48573641da2b0475fcd140e9. Chain 2 (Bitcoin): anchored in block 954689 (2026-06-21T10:35:31Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/e3d5ebd7-7c14-4e08-9b03-43a925eb0c11.json and https://artists.proofprofile.net/proofs/artist/e3d5ebd7-7c14-4e08-9b03-43a925eb0c11.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 0xe96f7d222490c4e1919e30a53e3004e0ae4d802f8a862c960189cc1794d3789a. Chain 2 (Bitcoin): anchored in block 960216 (2026-07-30T06:39:12Z), 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/NL2DY1400020.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x15aa16c32408c7d28e699480b753ad3e920b40217478c08329426cc79efb50a0. Chain 2 (Bitcoin): anchored in block 960273 (2026-07-30T15:42:38Z), 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/NLD681301921.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf83df152043ee1cb2b52d821cf486281eb731409f8865ff9c2a49dd5c88c8ea8. Chain 2 (Bitcoin): anchored in block 960288 (2026-07-30T17:41:38Z), 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/NLD681301923.