Sunflow is an open-source global illumination rendering system written in Java. The project is currently inactive; the last announcement on the program's official page was made in 2007. References
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 0x963a3621468ec622d7b7b6b4d72e4108962fe21c5c8a8a89d566f9f2446c9f6b. Chain 2 (Bitcoin): anchored in block 953819 (2026-06-15T18:31:52Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ff679dc3-cab2-4484-b97f-d7b0bc7054ea.json and https://artists.proofprofile.net/proofs/artist/ff679dc3-cab2-4484-b97f-d7b0bc7054ea.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 0x5a3f2770714edf3041c5b9bab9c3a36a3d5040e239630d38fec56a108f3987a9. Chain 2 (Bitcoin): anchored in block 958942 (2026-07-21T00:24:07Z), 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/TCAIQ2431217.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x17a73282bf6907c0cd71121c9a981670f156b1aa3847a476013500ec38baddce. Chain 2 (Bitcoin): anchored in block 958371 (2026-07-17T05:45:43Z), 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/TCAIR2431235.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x629b21056fe3d2995fb88348ea0a3b66a3a7e6a5363dc183033dcbb291cd4d8b. Chain 2 (Bitcoin): anchored in block 956420 (2026-07-03T00:42:11Z), 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/TCAIQ2431251.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcf72d36dc0dda25568879639a86b3d1196e1dbf1cf365771f1bdb1aa641186dd. 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/TCAJA2468313.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3bc2d5217a16ff9ebab9d116fd572b5ec942fa61568a04d987ed614c28369da3. Chain 2 (Bitcoin): anchored in block 958152 (2026-07-15T12:00:27Z), 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/TCAJF2538999.