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 0xc06a0809fb7feefc22180144277e5019043b02fc2d76fa70b2c06a924b3ab9f2. Chain 2 (Bitcoin): anchored in block 953408 (2026-06-12T19:28:13Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/be0f30f3-00d8-40e9-8252-4936aa91ba9b.json and https://artists.proofprofile.net/proofs/artist/be0f30f3-00d8-40e9-8252-4936aa91ba9b.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 0xaaeef85c91ce4462166b42eff2daea132ebc0976b07cb6b987ca2e37e7700e57. Chain 2 (Bitcoin): anchored in block 959026 (2026-07-21T18:20:56Z), 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/KRA531004005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0a4042b5eb5a63cffeb38ec4711b1fe245057b3a96906475688c4ccf463e6624. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), 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/KRA531004006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4b94fe4ab1065bb91611e9eb74644e2f3e34c58a8b2b44cb4b49aaac2003776a. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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/KRA531004008.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8c6c7493b49653d43b1a3408177f169d53a764cfe773241d47ad8570b29c423e. Chain 2 (Bitcoin): anchored in block 956841 (2026-07-05T22:14:35Z), 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/KRA531004012.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaaeef85c91ce4462166b42eff2daea132ebc0976b07cb6b987ca2e37e7700e57. Chain 2 (Bitcoin): anchored in block 958690 (2026-07-19T07:14:39Z), 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/KRA531004005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0a4042b5eb5a63cffeb38ec4711b1fe245057b3a96906475688c4ccf463e6624. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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/KRA531004006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x433bf6b46f929cf5ba22c4b2ed91303591c8551804e7c7173e6367ceaa73de9f. Chain 2 (Bitcoin): anchored in block 958980 (2026-07-21T07:04:12Z), 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/KRA531004007.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4b94fe4ab1065bb91611e9eb74644e2f3e34c58a8b2b44cb4b49aaac2003776a. Chain 2 (Bitcoin): anchored in block 956776 (2026-07-05T10:59:37Z), 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/KRA531004008.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xde9c33ca0f6bb834e4beaace474858a3a043086633458ab28289d6128269d3cf. Chain 2 (Bitcoin): anchored in block 959047 (2026-07-21T20:38:43Z), 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/KRA531004009.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x16c530a8f5f9898e26a3f87b4e89bec4f7a0d85ee081637304ad4c80575000b7. Chain 2 (Bitcoin): anchored in block 958728 (2026-07-19T12:24:55Z), 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/KRA531004011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8c6c7493b49653d43b1a3408177f169d53a764cfe773241d47ad8570b29c423e. Chain 2 (Bitcoin): anchored in block 956656 (2026-07-04T14:03:39Z), 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/KRA531004012.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4894b4da24a8b850993ae3970329d62f83b310a469c5fd6feee43ec4af1981e4. Chain 2 (Bitcoin): anchored in block 958980 (2026-07-21T07:04:12Z), 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/KRA531005004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6aa71be6160a9e26c8ce11cd378a8a45149c7aea42dd5f51df3e23fcc8f05a9c. 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/KRA531005008.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6f320fd798adc94442efcfb830ca6ece6a447ee9d2cd8e157b59bb0dfa9b03e4. Chain 2 (Bitcoin): anchored in block 958765 (2026-07-19T20:19:28Z), 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/KRA531004015.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdd8374369fdf1a669d01fddc79955dea7c8a856960e398e819de38ec9b73d4fd. Chain 2 (Bitcoin): anchored in block 959073 (2026-07-21T23:25:37Z), 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/KRA531004017.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x436d5f4c0ef57a257b287588501de5a79b897d2af6d3e72fd1876b650bbd1676. Chain 2 (Bitcoin): anchored in block 956639 (2026-07-04T11:19:20Z), 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/KRA531004023.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf5a89b68bd1c4be353d5427cae3001a81f7ae5a77a712d32d30c32c8b819da9e. Chain 2 (Bitcoin): anchored in block 958286 (2026-07-16T12:43:37Z), 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/KRA531004026.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6f320fd798adc94442efcfb830ca6ece6a447ee9d2cd8e157b59bb0dfa9b03e4. Chain 2 (Bitcoin): anchored in block 958208 (2026-07-16T01:18:35Z), 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/KRA531004015.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdd8374369fdf1a669d01fddc79955dea7c8a856960e398e819de38ec9b73d4fd. Chain 2 (Bitcoin): anchored in block 958987 (2026-07-21T11:04:25Z), 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/KRA531004017.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x649c87fdfb5c60360dcb14288c989d4759c6eef490e3a8254f52a77e902848cb. Chain 2 (Bitcoin): anchored in block 956822 (2026-07-05T18:48:28Z), 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/KRA531004019.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x436d5f4c0ef57a257b287588501de5a79b897d2af6d3e72fd1876b650bbd1676. Chain 2 (Bitcoin): anchored in block 956476 (2026-07-03T09:04:44Z), 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/KRA531004023.
러브 홀릭 (Original Television Soundtrack) - 사랑하니까
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0be175acd85eaf3bdb55cc52e714aaeadce0d8dac89e6909fbcea3f11eb21d09. Chain 2 (Bitcoin): anchored in block 958805 (2026-07-20T02:22:58Z), 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/KRA531004029.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8c04c9da9661febef173eb12504228969ac097f077e2a9c3952ee170d67bfcda. Chain 2 (Bitcoin): anchored in block 956894 (2026-07-06T07:53:57Z), 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/KRA531004031.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x85a34f6a24fbf1ed5ff1d97edab978d3bcc91b76dff16363ce482f808e50e26b. Chain 2 (Bitcoin): anchored in block 956474 (2026-07-03T08:56:35Z), 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/KRA531004036.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1560b77fca839e07e8a92c3219ea20b282b12013d2384668dd37f517caee5aee. Chain 2 (Bitcoin): anchored in block 959024 (2026-07-21T15:31:18Z), 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/KRA531004028.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0be175acd85eaf3bdb55cc52e714aaeadce0d8dac89e6909fbcea3f11eb21d09. Chain 2 (Bitcoin): anchored in block 958447 (2026-07-17T19:47:19Z), 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/KRA531004029.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8c04c9da9661febef173eb12504228969ac097f077e2a9c3952ee170d67bfcda. Chain 2 (Bitcoin): anchored in block 956639 (2026-07-04T11:19:20Z), 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/KRA531004031.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x03987b030b05063ad24d16ab4a1d8a07211a15d8e434ca6a5d085a20817b8873. Chain 2 (Bitcoin): anchored in block 956422 (2026-07-03T01:01:38Z), 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/KRA531005020.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x789190f93ef87cf4e8da9f7ceb88046c34ff681d8619a82fd5745a1d1e904829. 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/KRA531005021.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1384680d973243d3f6e279e5d87332667516cd88f856028017fddaee9d3ab26e. Chain 2 (Bitcoin): anchored in block 958905 (2026-07-20T18:36:22Z), 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/KRA531005025.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf4ac1f5eec88f8d0364b9ff2e6528cc2700ec987ec78945150f2c2ed05f54261. Chain 2 (Bitcoin): anchored in block 958170 (2026-07-15T16:21:50Z), 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/KRA531005026.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x03987b030b05063ad24d16ab4a1d8a07211a15d8e434ca6a5d085a20817b8873. Chain 2 (Bitcoin): anchored in block 956639 (2026-07-04T11:19:20Z), 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/KRA531005020.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x789190f93ef87cf4e8da9f7ceb88046c34ff681d8619a82fd5745a1d1e904829. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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/KRA531005021.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf4ac1f5eec88f8d0364b9ff2e6528cc2700ec987ec78945150f2c2ed05f54261. Chain 2 (Bitcoin): anchored in block 958627 (2026-07-18T23:33:54Z), 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/KRA531005026.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1a5b47437dc0221dd982c32ea5476d656aa46386a5ac5335808606d9b93abe3e. Chain 2 (Bitcoin): anchored in block 958905 (2026-07-20T18:34:09Z), 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/KRA531005032.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaff2dbb9be3e4e9934a6ac1dbddb28a3da9434b77dd87f6b5d052862228dee52. Chain 2 (Bitcoin): anchored in block 956551 (2026-07-03T21:18:05Z), 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/KRA531005039.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaff2dbb9be3e4e9934a6ac1dbddb28a3da9434b77dd87f6b5d052862228dee52. Chain 2 (Bitcoin): anchored in block 956826 (2026-07-05T19:27:56Z), 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/KRA531005039.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2e4596994885646d57a101788f5f16da229f6bb3c42685beb8fb5671b8d0f14b. Chain 2 (Bitcoin): anchored in block 958420 (2026-07-17T13:33:01Z), 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/CAENV2520445.
Que sera sera (Original Television Soundtrack)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6ca7ea9409190ab3dab97fcc174028563b2eb3445bb1f53b3170b7da8b4ff43d. 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/KRA531004018.
어느 멋진 날 (Original Television Soundtrack)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xad2adddb8aefba66ecf7d92d444997b2400062824e7af29ce1c54a35f5690ca5. 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/KRA340908602.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x08165d62ee2db236e11ff7a068f91e313fde5735b0fbb4448abccf277aa98086. 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/QZEKE1926951.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd26986635d33a2d76201763a679901fed0cb327d5a1d93dbdcc7094ff58d4a95. Chain 2 (Bitcoin): anchored in block 960478 (2026-07-31T23:30:38Z), 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/ZZA0P2401212.
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