Irving Robert Kaufman (June 24, 1910 – February 1, 1992) was a United States federal judge, first on the U.S. District Court for the Southern District of New York, and then on the U.S. Court of Appeal
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 0x1f90da01034944833af671b2a99fca77563b0364e52e75419634b91b2960529b. Chain 2 (Bitcoin): anchored in block 953727 (2026-06-15T02:33:01Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/8ec4e10e-44f2-478b-906f-191eceea2542.json and https://artists.proofprofile.net/proofs/artist/8ec4e10e-44f2-478b-906f-191eceea2542.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 0x0771f8e3afa7785627eec2e46d1924c3eab7693ac704b686306f67b45e66e638. Chain 2 (Bitcoin): anchored in block 956484 (2026-07-03T10:47:44Z), 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/DEXO52490347.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x61cf4c0b39d6ac36970b8c3fdb52fa7309f91d5712bfc6e14cd398141eb985a0. 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/DEXO32237192.
Ten Little Fingers and Ten Little Toes (Down in Tennessee)
(You're in Kentucky) Sure As You're Born
Wonderful Nonsense: Fun Songs of the Roaring Twenties
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbbc1ae4327dd10628c7075ee862551614221ddc6c27e44d37de076077baae2d1. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/TCADL1870125.
The Naughty 1920s: Red Hot & Risque Songs of the Jazz Age, Vol. 2
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf7ddab0e71bb2f7cdf4e55a79ec1bab21261e223a1a27fc956496c1d971d3664. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/USM2U0804404.
The Big Broadcast, Vol. 10: Jazz and Popular Music of the 1920s and 1930s
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb4c38807bdd290f8e39d2d72ed345b12cd889427242350c36c15e5c5e62b8754. Chain 2 (Bitcoin): anchored in block 960418 (2026-07-31T15:20:15Z), 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/QM4TW1514096.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2c617659e083ee920ecac29934f4a96a9b27eda494d74ad9c59bdc215858fc56. 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/USXTG1100818.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1ba64cfcbc284ffc9e88db85c70b94299ce2885016034d3424e026ad8ac83620. Chain 2 (Bitcoin): anchored in block 960410 (2026-07-31T13:50:38Z), 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/USXTG1100827.