thumb|Solidus of Emperor Constantius III __NOTOC__ Year 421 (CDXXI) was a common year starting on Saturday of the Julian calendar. At the time, it was known as the Year of the Consulship of Agricola
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9be8c349c2772703bb4cc8435c53da69c55c4c61471bc4fc8f656c8d91c990f9. 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/1346dd72-c5bc-4888-ba7f-1c0d2d8f5fda.json and https://artists.proofprofile.net/proofs/artist/1346dd72-c5bc-4888-ba7f-1c0d2d8f5fda.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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x13474791eb6f51d39a4933151834eba2dc49f6999108cbcca898d364d0a53229. Chain 2 (Bitcoin): anchored in block 957759 (2026-07-12T21:46:51Z), 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/TCAIX2456465.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x35db9403c51078772a7cccc2639115bfe3dec7cdf907f5648ee10f90fb6509f2. Chain 2 (Bitcoin): anchored in block 956560 (2026-07-03T23:28:02Z), 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/TCAIX2456483.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x18b5333857475214c78bf68dc7bc9c135375c927fd519cbbaf71e982bb421cdb. Chain 2 (Bitcoin): anchored in block 956420 (2026-07-17T04:48:40Z), 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/TCAIX2456441.