Cologne ( ; ; ) is the fourth-most populous city of Germany and the largest city of the German state of North Rhine-Westphalia with nearly 1.1 million inhabitants in the city proper and over 3.1 mil
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 0x5d4833a5038dd183deca5b7297b44fa6922e71f4d7db9d9911e3ce0633b4a8c5. Chain 2 (Bitcoin): anchored in block 953636 (2026-06-14T13:03:42Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/36bbe1eb-9aa7-4b85-b2e0-30a5cc38961e.json and https://artists.proofprofile.net/proofs/artist/36bbe1eb-9aa7-4b85-b2e0-30a5cc38961e.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 0xe2bdc8e0b32dbca43335601917c74f3f2e601b61fd99a52f8f0cd5870b079eff. 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/USA2Z1901293.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd46e54a4b7d35151d2dca2daa9c2ecba841cabbac4acb93f2ad35f5c538ba514. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/USA2Z1901296.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x412929b2a2566a6e6ecccd1f6a6e931a58a49c363d6d85f4a6bcf5d57d2fbb46. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), 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/USA2Z1901297.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2a7d0d88cd89291f1095450b6d41cf01c4993697e95869fe223e73c087f59bd7. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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/GBP6T1900301.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd7db96d52b513faea837096331a1b61f13f046d194062e03f93c9582a445387e. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/GBP6T1700219.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf4e1eecbb0fbe779d169e19faf6e8555cf915484038c90e9993a15e4e00bf3da. 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/GBP6T1700225.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1e5ee6ec57a478d5de19b13869c3c2c849ddf19bd238d182aec2dc106db58f0c. Chain 2 (Bitcoin): anchored in block 959107 (2026-07-22T07:19:23Z), 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/USA2Z1901292.
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 0x0543a82eb9ba6f3f1b3c7c84cbf26814d6a9af0f5fba5ce8eeca00cb059fa6cf. Chain 2 (Bitcoin): anchored in block 960113 (2026-07-29T13:38:16Z), 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/USA2Z1901294.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0bd353d44c3fedbe61be4e9353f198eba004cc339d8f747ce1e75b5d5888d2f3. Chain 2 (Bitcoin): anchored in block 960111 (2026-07-29T13:21:01Z), 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/USA2Z1901295.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x32eeadecd828a6d2e618e4407db5bcfbc70ab45d2663425373c25e1ba57576e5. Chain 2 (Bitcoin): anchored in block 960144 (2026-07-29T21:09:47Z), 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/USA2Z1901298.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x994f08e2b00436858f248a9a098a996eaeb17be9475421fe69d205d35b322c22. Chain 2 (Bitcoin): anchored in block 960138 (2026-07-29T19:35:34Z), 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/GBP6T1900291.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x385a000f588e396ddd229dc86034b7874a5cc787c831e4ac042740f9c64aeb16. Chain 2 (Bitcoin): anchored in block 960207 (2026-07-30T04:47:22Z), 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/GBP6T1700233.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2193b6c76b907fe6661beee99fd181f1cecfdaedc1025186036f5efe9fd64009. Chain 2 (Bitcoin): anchored in block 960348 (2026-07-31T05:17:02Z), 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/GBP6T1700239.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x872e6635b0db72585a3d1187f2639c800e4056456159b627174a7dd02b30822f. Chain 2 (Bitcoin): anchored in block 960209 (2026-07-30T05:15:54Z), 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/GBP6T1400129.