David Cohen may refer to: Academia David Cohen (historian) (1882–1967), Dutch historian, Holocaust survivor David Cohen (rabbi) (1887–1972), Rabbi, talmudist, philosopher, and kabbalist David Cohe
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 0xf552ee7aae9347130c237770ff39ba8e51d2a241b12ed0c96a5f3eaf1c3d339a. Chain 2 (Bitcoin): anchored in block 953626 (2026-06-14T11:41:45Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/23fd7c2b-f7c6-4c3d-bf07-dfdf8e0834db.json and https://artists.proofprofile.net/proofs/artist/23fd7c2b-f7c6-4c3d-bf07-dfdf8e0834db.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Bachianas Brasileiras No. 5: I. Aria (Cantilena) for Clarinet and Cellos
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 0x9253f5719914e9ed5f326959220dcbbc012b43d5f001789ee5acc733253b5c61. Chain 2 (Bitcoin): anchored in block 957067 (2026-07-07T16:54:37Z), 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/USLZJ2286081.
The Budapest Scoring Orchestra and Choir
Lords of the Fallen (Original Soundtrack)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd477b6510950f8700fc65e0264052eef0323878b4df506d69c917cb3c92fe59f. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/UK9AV2301918.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xeeed403084c438bd1127076158f0c522cbde42a5f49dfec2b23f657e0b131a52. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/UK9AV2301950.