Christian Köhler (13 October 1809 in Werben – 30 January 1861 in Montpellier) was a German painter, associated with the Düsseldorfer Malerschule, although his style owes much to the Nazarene movement.
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 0x131714383fe08f9096c3b5d724582076bf58a0f9a6a954674453ce8a666b6785. Chain 2 (Bitcoin): anchored in block 953610 (2026-06-14T07:58:09Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/133e9fd6-db2b-407c-8f95-3045886d5f98.json and https://artists.proofprofile.net/proofs/artist/133e9fd6-db2b-407c-8f95-3045886d5f98.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 0xd1aca0945c7b0f0bba5285e289d11efbdf64b7076746b1174ca4760eae44eeb2. Chain 2 (Bitcoin): anchored in block 960368 (2026-07-31T08:26:41Z), 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/DEE282382501.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcb441ff0aa35b8a8d6afc700183734897d31d2c53a1e6e7474c04d15e415dd19. Chain 2 (Bitcoin): anchored in block 957052 (2026-07-07T14:50:41Z), 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/DEE282382502.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xba400bdfa89207cf1203773206f4cfeff93977f0522485225cd36ae4ee34eefb. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/DEE282382503.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7db6ec4b578108a28a7c823d86a16aa151c62071153569653bc09313138a1b00. Chain 2 (Bitcoin): anchored in block 960337 (2026-07-31T02:51:48Z), 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/DEE282382505.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3d8fb5c69f88b0e44cc1ae25dcfcf25bb977a128de8d2a0ac555f91f1754c43c. 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/DEE282382508.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf32c7d97a53cc96e4305f20c689755bd70fd5aa495b4c51449be55302f81fe93. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/DEE282382510.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf63676ccdd08eb7860ab0660a8f3c4d3f8169eb0f58d531a8fed6fc842760230. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/DEE282382512.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2c066ab67daa21c040b885d26f0050277e112ba0f1bd083d49b93ef5a3756012. 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/DEE282382513.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9c72e248076b8edd2628730a97f64c516a2cf6b07fd77f63e4f8da08f459848a. 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/DEE282382515.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2a085dbcdd450dc4dcbfb56efabe8ee65db50de782bf7b7a37233311099afdee. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/DEE282382516.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x84045a5d37570f402486390435a4255913edbab11357b00c63fba788d8e932e3. 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/DEE282382518.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7198122dcfa6ce30b50a8aa0f539ec8b78c3270a11a610ac8d5ffdf698854e03. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/DEE282382520.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc79e6f2c2c9fa952eeb8c7a87b28e238402c39d57e973dd37f66740bd591d2e7. 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/DEE282382521.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x351273c9d5c1662bf7d9923fbd7c755e795b9f563b1b60b644fb431be34e3ab7. 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/DEE282382522.