Sienna () is an earth pigment containing iron oxide and manganese oxide. In its natural state, it is yellowish brown, and it is called raw sienna. When heated, it becomes a reddish brown, and it is ca
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 0xa280f522a62ca095184c189ea19090571c10170e4a04f4db518f75fe1c0377cb. Chain 2 (Bitcoin): anchored in block 953678 (2026-06-14T19:23:11Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/626e76eb-9df9-459c-a50d-cb1c169eaf1a.json and https://artists.proofprofile.net/proofs/artist/626e76eb-9df9-459c-a50d-cb1c169eaf1a.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 0xe7741583d0e5db6fd86d8a0926e2bbb8f972b99c9bdbdb65c821ac4ebd2ea117. Chain 2 (Bitcoin): anchored in block 958571 (2026-07-18T15:39:25Z), 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/BXSPI1700003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x737178d1cd9cd71bc319c37c3822a7b47ae37e4440d2e139b7f9d4231a0ddb5a. Chain 2 (Bitcoin): anchored in block 958639 (2026-07-19T01:18:30Z), 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/BXK152000003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x355c7c0fe6235680ac20dfc5d6f92ea2631e630260d9de93fc7ab218223ffd51. 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/BXSPI2000001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x39503f745572e68621039cab6a9c5381442178fefcc3a9c620e4999fd04adc49. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/BXSPI2000002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc1a8b6f3a751680036ab194f678293c7cc464d96317f9970f38aad318171c5cf. Chain 2 (Bitcoin): anchored in block 958746 (2026-07-19T15:36:35Z), 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/BXSPI2000004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd67291473f4587e556fa764b607017e84d37e6334869b2993dd3207e03880d0d. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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/BXSPI2100001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1ea522bcb6c3733bebae66b746d75ac56f23507ab5e81814f2af7c06c5c1182b. Chain 2 (Bitcoin): anchored in block 956375 (2026-07-02T16:51:38Z), 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/BXSPI2200001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x575726e30cd4a3525e31c1480cc4d5905f7f75dfc6c08616d3c3333092f19cc2. Chain 2 (Bitcoin): anchored in block 960500 (2026-08-01T03:13:03Z), 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/QZPLS2189899.