John Francis Duff (January 17, 1895 – January 8, 1958) was a Canadian racing driver. He is best known for winning the 1924 24 Hours of Le Mans. Early life Duff was born in Jiujiang, China, to Cana
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 0x093aa85d6ec31815ab3e274856b17f0e44af78c8f3161c3bea93ba9a57533c41. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/f29a3c88-1e08-4f87-93dd-a1b6f50c8d24.json and https://artists.proofprofile.net/proofs/artist/f29a3c88-1e08-4f87-93dd-a1b6f50c8d24.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 0x466be856a24616e03b716c7d3a6c04513b9592b7301d58f7301fffa140e9cdbd. Chain 2 (Bitcoin): anchored in block 959128 (2026-07-22T12:33:25Z), 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/QZS7J2489375.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0f884cadbec7861dde5396d7ac0da3c1f8acca6f6297cfb057b20e3a0ed1c84b. 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/QZS7J2465589.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6e1439c6b56451f9ac1490a048cfc7fbe6503065b1b5c1245c862be3ffb64c7b. 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/QZTLA2589995.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9bf594426a487f5e5ab8b10afb8227d5a0fdf75899e698716351d5dda8c76e66. 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/QZQAY2401471.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcbab59909a1ffd071c769524263e1bd7de0e2850529deb56516aba9afbef0b47. 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/QZTLA2528113.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x90e71999c7c53cd3824f6c0180fc4baf5ea25faa631ca2e90f753aab11e224e3. 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/QZS7J2466510.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbc6fd22bda5be7cd1de944f5b22e4b771a3fef2598f49126f167cf69e2c14142. 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/QZS7J2452738.
Be Your Girl (Eric Kupper Remix) / Total Eclipse of the Heart
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x59ce4f27950bc6682a6bdbcb760e35448ddbcc328b791de1ebf39a73c3ae859b. 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/QZQAY2487543.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9bf594426a487f5e5ab8b10afb8227d5a0fdf75899e698716351d5dda8c76e66. 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/QZQAY2401471.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xefc7e3aea53c1c0ba76c8b7ac2404c50049a7a420bdaa39c2dc0dfc33fa7aecb. 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/QZQAY2393596.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb5b4d1313bef2f23c3519b51d53e5ef82fd57929573e0ce19b3f85e5a94d3778. 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/QZQAY2314820.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8cf2e46cbfb6209c571bd9a3bc9b219e8b2be18ba0f14ae470a8c54a43c0b906. 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/QZTL92354381.
Is It A Sin (Block & Crown and Nick Fiorucci Remix)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x64a30e41ced9388a222835a88166d1c8bbb57efc8ec767d1b315dc28a8742120. 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/QZHNB2215243.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa344d5fe77b3aab3845fa41c5f49ab821ec9fb8eb19a42a8e36db6761c9bc6ef. 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/QZHNB2215244.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1a0615caac7c921e28d624b0c6bb66dafd40a5269651fa654273e9aa8b0ddd6c. 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/QZS7J2125474.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa3fd30cf05f3e1756d3733d51a378b59b16583bd5ccc4b4681ea3443075c2d38. 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/QZQAY2164951.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x54036af42cfea1b2127f687a5805a22f0667511d6fd2fa670642a6077450968a. 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/QZQAY2163726.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x73ed94a4e114075eb69bcf5c4a1a115e0b778462678b119011e4280352ca1ea1. 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/QZQAY2150609.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa16551dcb54e1a6fc23f11fc835c4ba057249c11abc531b1b95670b95c3a896f. 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/QZQAY2132455.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xce64c401b3ccc22e526e335e17347a7aa4d4ffeda602f3f2921849e74a2d43ba. 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/QZFYW2135988.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2746e34114fb24afacf30c2bb2b9f4a9844d828bf841400d5c21b36628cf3484. Chain 2 (Bitcoin): anchored in block 956312 (2026-07-02T05:09:12Z), 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/QMGR32168209.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcadfb000fff45438b93e5507892b44f9239483f78f6f55089b71de3b21901ba4. 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/QZK6L2092052.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x013b6e32a074dbd828d2c070c9ada3dcb0254385ad3b953a61578509e53be6c3. 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/QZK6L2051124.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x32a613144a6ff3d570db0d100425631f724139872db368103d27ce4b4c7ee468. Chain 2 (Bitcoin): anchored in block 959123 (2026-07-22T11:35:32Z), 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/GBKPL2084022.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4eb74da6eaa0b6dbb931efa1cdc88e71127cd920af8a1e781462ae9df03b9ebf. 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/GB8KE1955657.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa6c688ff9581a183cc6b78906d244d95a37279c99a760943d8b01391e47f70f2. 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/GBKPL1963751.