The Common Object File Format (COFF) is a format for executable, object code, and shared library computer files used on Unix systems. It was introduced in Unix System V, replaced the previously used
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 0x625744646b2399dfc03fc444c51fc9455767b716764f9c31d766dcddeebda2e2. Chain 2 (Bitcoin): anchored in block 953674 (2026-06-14T19:07:16Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/605c6093-2745-49aa-9c17-9eab41c5b8e5.json and https://artists.proofprofile.net/proofs/artist/605c6093-2745-49aa-9c17-9eab41c5b8e5.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 0xe821cc333417020339359db073c2e5a0b3116ee98fd92dd252ddda91c077407b. Chain 2 (Bitcoin): anchored in block 958520 (2026-07-18T08:19:09Z), 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/QZWDD2269154.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf339bf91922c39d66c23bd23029ac5fd93a576426fcf0cc536176b13586e47cc. Chain 2 (Bitcoin): anchored in block 957882 (2026-07-13T16:48:10Z), 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/CH3132419150.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x05abe7b36959469fc8e406acb94c1bd5db53d12b2fad62a2bbba04105e365723. Chain 2 (Bitcoin): anchored in block 958749 (2026-07-19T18:39:37Z), 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/CH3132419217.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x33da2e8bb7a096955bcdfad46917deb2bf46cc8c412953b9006df6937354c93f. 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/DEPI82530374.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc9f861937e765ab9f2525c9cc8791f7830df8b1238eea4b117a7ee05df9c150a. 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/NLF712409920.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbe91b29bf96dc0202ae2ad706a7430e00d6a4d3837e5d848e59efa1767fcbf1a. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/NLF712408445.