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 0xc60958dadfad3996c12df506b525a2e939768b354ff4cf1e7d25910cfb2a3dca. Chain 2 (Bitcoin): anchored in block 953768 (2026-06-15T09:30:06Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/c142fc00-8899-409a-aff7-fe1dab4e9ecb.json and https://artists.proofprofile.net/proofs/artist/c142fc00-8899-409a-aff7-fe1dab4e9ecb.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Witold Lutoslawski : Intégrale des oeuvres pour Orchestre à cordes
Cheryl Frances-Hoad: The Whole Earth Dances
The Music of Upstairs and Downstairs: Upstairs Downstairs Theme
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 0x6598139fa2f2ceb56115517f3d44e3134a5321fa2400eaae2a63d00c59203783. Chain 2 (Bitcoin): anchored in block 960397 (2026-07-31T12:24:41Z), 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/GBUXE1201801.
The Music of Upstairs and Downstairs: My Perfect Sister
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa1e6a74777e8018a1732912313b351ba7a54fd104967029b2e412782eb181ad3. Chain 2 (Bitcoin): anchored in block 960435 (2026-07-31T16:33:26Z), 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/GBUXE1201802.
The Music of Upstairs and Downstairs: 165 Eaton Place
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1a1e457cd41ed3faad0d35d4d9321127b2e6fbca3d5015133cdef45d8d8ea3f7. 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/GBUXE1201803.
Linda Richardson Sings Italian Opera Arias
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf8df0d35a58aa13835a155655b8eb2a75d4afd3b15ee326e0fd305ba304b6ca0. Chain 2 (Bitcoin): anchored in block 960160 (2026-07-29T22:48:59Z), 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/DEA117400010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd428b50e8b50d6c579f964082251580612abf13b24822f2c707c31552b3ee1d9. 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/DEUM70802658.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6862c4e11896601f2b78b0758935b464286d854505f0e4a1c5e5a1a91e9c8881. 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/DEUM70802659.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaa4a0f5d4059fd3ee30cc4ff698bd3b820cb221168f48a928c301159c23e8dd3. Chain 2 (Bitcoin): anchored in block 960284 (2026-07-30T17:23:26Z), 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/DEUM70802660.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8609dc485e1ab95a9fa28ad7c8a38ca040e6d30554ede04965d3fb5148e5b819. Chain 2 (Bitcoin): anchored in block 956889 (2026-07-06T06:56:49Z), 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/DEUM70802661.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0e9d287ce88b577ac41b56eb9330b5aa9f66142c21de0888dfbf379118587553. Chain 2 (Bitcoin): anchored in block 960264 (2026-07-30T14:36:16Z), 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/DEUM70802662.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x520824c8cf4d2913d8f0e902fcda6708abc4922cd815cbc31858df538c61e1bb. 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/DEUM70802663.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7990bd33e320038de034b637aeccb75735376f6eaad60e34ea45ce33441f8209. Chain 2 (Bitcoin): anchored in block 960284 (2026-07-30T17:23:26Z), 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/DEUM70802664.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe7500b9b96b24ae1ef59b6385a7524da78e83b218141e5c94379492036d48277. Chain 2 (Bitcoin): anchored in block 960203 (2026-07-30T03:35:13Z), 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/DEUM70802665.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x84bd9242bc14fbeda623d5d5cfa277a658cf761f85595e0f315680d92b399857. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/DEUM70802666.
Stolen Rhythm: Works by Cheryl Frances-Hoad
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5e82034a7a25b188715d45b46a8ddb7ab8d584252a37b3faa3f5330920d9098e. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), 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/GB4ZK1600128.
Don't Try to Catch a Planet (with Your Teeth) [feat. Jody Gray & David Cohen]
Poldark: Music from the TV Series (Deluxe Version)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa4cbab5468f8ee2043003d30d8233ee624bfc3019770fab060bed961961809b8. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/USSM11601586.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xac4c8aee1e97452d210bde29b1e3e960b145609e904cffa68a8e51b126582ef0. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/GBARL1601151.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xecaf413ab01d5e9bde1a993bbdfbe352b638a9e41f7b2f71ed7d9d863301389c. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/GBARL1601152.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf6c66d6a49490a16c598907221a0c12596d1eef766a39010aeb7810aa3d132cb. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/GBARL1601153.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2b936ea1af423ae2caca52cae9de7aa17ddc65ce9f36ce2cae3a16ea5775a80d. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/GBARL1500451.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x26b9c8cd1c934b3d4c92b7e74510f04cfdf4cb0b68875f8a1fd506cec19ac156. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/GBARL1500452.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4e329299859de9f342df56ed2548f8c678c926e1487e23941200332c071fcccc. 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/GBARL1500453.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x96abb8c204477671bbbac2c6459ff2491bc9356f744975c13d970cf20edbf79f. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/GBARL1500454.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4789d764ec27718d315f9f75193138c25b03f6bb712951ff7e5afa9bdbdf9c8c. 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/GBARL1500455.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7b0cf1756946b3c3e40c55e2f7dc280f87d69d0a103184126f50d6c0e1613d0a. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/GBARL1500456.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xadc4d5dc9ab845ad091eac465cc264529dfe666182461ef4470598bb50656a73. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/GBARL1500457.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe227d2bf99c7677667e2322ef22a2de65430b6cc1411114a16523a5ed799a2fa. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/GBARL1500458.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0e61af7091a09da764cbf7088d5fc7b73874ca26706a09079d673d89a09b9ab0. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/GBARL1500459.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xce97c984468f4758bfe0f246a5366783417070fed953b982ad0c7a77722759f8. 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/GBARL1500460.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x949216947b61dd41562a7c2751d248b3bd532a2da2790a7294bc78ae2625610b. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/GBARL1500461.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdcb0ccfc7e72df0ea1a14cd460b4f90bcbd920d493edeafb6432568f48da3c67. 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/GBARL1500462.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x46a4f6d4ae81106cb7dc059ff53d32ff4369d45916ec0b7c2cb7036872362796. 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/GBARL1500463.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd869528f1b3da0d2ccd238c9e1d13070c68b6f4f1c2452f8932d38c57544c168. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/GBARL1500464.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9032c8b6df01c2092b0364ad3d2e2dc34470a670af2094230209ad44da4e1d29. Chain 2 (Bitcoin): anchored in block 954130 (2026-06-17T19:07:14Z), 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/GBARL1500465.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3399ce1bad555db3ed43727886ef882c904056ab7cee929a4d739691c7f3b7d8. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/GBARL1500466.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb94c906fb6480772b71fdac0c15f43c919ccca8fa47f8b3b7782ae0d6a22ec59. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/GBARL1500467.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd1d65086f618e450ed3ae191fed1d313eb4fc6b3e6aba0c43a782d4438cf5eeb. 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/GBARL1500468.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa3539f5dda347e24321ff7737bee201dbdf6492d362ba3687553949d06ca14af. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/GBARL1500469.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7df568603df7be01582f83db69337f28ae52ea05d110624ef98d0e2941684b35. 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/GBARL1500470.