thumb|right|upright=1.35|Barbershop quartets, such as this US Navy Band ensemble, sing four-part pieces, made up of a melody line (normally the lead) and three harmony parts. In music, harmony is the
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 0x501e863777429ab0830ea09a290dca7a80ef594af0d81b5c6308e3d16b2a98db. Chain 2 (Bitcoin): anchored in block 953423 (2026-06-12T21:20:00Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/fa36a3d6-4a58-49df-81e2-02da58ba7ac6.json and https://artists.proofprofile.net/proofs/artist/fa36a3d6-4a58-49df-81e2-02da58ba7ac6.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 0xfe4b9f6ef68ae1b6498e0ecf96f5a17c81962c6129c5eb26ef6ee6771752896c. Chain 2 (Bitcoin): anchored in block 958208 (2026-07-16T00:43:02Z), 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/QM6P42329470.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4c6382dcb19c2dc506ddc582580dfaef685c4341bad9482c0c8c32a217b2f96f. Chain 2 (Bitcoin): anchored in block 958392 (2026-07-17T09:46:31Z), 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/QM7282317110.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8a0e2ff11f95341011376fa27ccc3b5c09c5d7a91ed67c1c48a09cf4fc0ce95b. Chain 2 (Bitcoin): anchored in block 958959 (2026-07-21T03:51:22Z), 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/QM4TX2481423.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf863ab786c91c2547bda023bb72b2c17cd43feab882bd6f66dd6f47772039b35. Chain 2 (Bitcoin): anchored in block 958194 (2026-07-15T20:32:27Z), 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/QM7282472392.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x62c8c89a8a35a5f0f2ce618587163fde7f10ca99cb9195b581c5248aa026d516. Chain 2 (Bitcoin): anchored in block 957891 (2026-07-13T18:21:04Z), 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/QM6P42469567.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8a0e2ff11f95341011376fa27ccc3b5c09c5d7a91ed67c1c48a09cf4fc0ce95b. Chain 2 (Bitcoin): anchored in block 958137 (2026-07-15T12:17:40Z), 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/QM4TX2481423.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa6e233db72f30df40496361bc43d7155a6cf7430c5b0c6e3e8f2f46c6129c000. Chain 2 (Bitcoin): anchored in block 959002 (2026-07-21T14:02:30Z), 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/QMDA62403038.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x92580ea2987ee6279af067facd03bd00bd10c215f8aebad5502f27b2d018d0ae. Chain 2 (Bitcoin): anchored in block 958823 (2026-07-20T05:46:34Z), 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/QMDA62419785.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1fde3bcc7c30589f8e3620635309276ed761b63dce1c15fe15168dbc2434c875. Chain 2 (Bitcoin): anchored in block 956440 (2026-07-03T04:03:57Z), 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/QMDA62402422.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x80e0d35eb585edd41d7a3a93cf24df544231253d9d38f2490ab6ef300363f1ab. Chain 2 (Bitcoin): anchored in block 956856 (2026-07-06T01:25:57Z), 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/QMBZ92468772.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x60361973bbe71f8d022240310fe7b57da838f6fded05c1a27d98556f015c7900. Chain 2 (Bitcoin): anchored in block 958690 (2026-07-19T07:14:39Z), 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/QM6MZ2514894.