The K21 is a South Korean infantry fighting vehicle. A replacement for the K200-series, it was formerly designated as K300 or XK21 KNIFV (Korea Next-generation Infantry Fighting Vehicle). The initial
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 0x0ca4c95e5db22f1eb648a6ab3f61969f923caf768f027093eaf03ccc52a8decf. 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/ffe82df2-f718-468f-8cd4-32c3ad7fa98f.json and https://artists.proofprofile.net/proofs/artist/ffe82df2-f718-468f-8cd4-32c3ad7fa98f.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 0x1f8ae8ebdcb28d66bc08b44d71f1066204fce90ef4b93b321654b2369a63d323. 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/AU5H41200002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x070fa3e0eb46ee463511126b4126195bba9994a8a0be6d34f0662be98c8dd348. 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/AU5H41200003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x879638fd3725ad427cc49bc0e364a849f76e729e47025cdd982ada669f3bedc3. 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/AU5H41200004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbe59433844c3c9d9e8d0914c1a3a86c89b8615d0e0557ac4d835da6dd6e6d168. 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/AU5H41200007.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x907a5e020626c5dbd945c1e774d41ab9ae22d1d362079dc6def2594493bb8f84. 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/AU5H41200009.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7a2abb1a2e9f07a0b5a3ee07f2006d73e8604df9cef6541241036ec1a25c95d6. 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/AU5H41200010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf605c6d8e7995f46cfaaf3f499ebd373eaa9d5bf119df9c4a4b025ad248c482d. 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/AU5H41200011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa4d4ba55545fc0b0f1a2f3f084fa66040b502b28e10fe5728156529b806fc765. 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/AU5H41200012.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2349bdc64e15291317ff95670dc7da82e163833a1fc2bd4e1d4156b08b31f6c7. Chain 2 (Bitcoin): anchored in block 960368 (2026-07-31T08:26:41Z), 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/AU5H41200001.
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 0xd805aa4b829a2e25df86b54a64621f0ba85031ef18846d94d4b3f9d4bca0bb96. 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/AU5H41200005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb436711cb65e7aeef32712b95709ce5d022b3a61855650ad1b7355c97b4e6413. Chain 2 (Bitcoin): anchored in block 960368 (2026-07-31T08:26:41Z), 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/AU5H41200006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8179c706132026003115cf5776e8e394dfba10ca6ae749f7020dd9a5a1b033f9. Chain 2 (Bitcoin): anchored in block 960410 (2026-07-31T13:50:38Z), 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/AU5H41200008.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb49704f64b05324b103fe366bfe3a453da7218a47a8c333f7ab34a65d9451e60. 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/AUK211700003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x40419ffc1a1b19195060901fdad02f1869b5d8b626f331477430860a98193d8e. 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/AUK211700004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfc108a171de838ba3bb5afafbd9d019a78e91ed11009be038162c8059985d2ac. 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/AUK211700006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5bd226f6bebe2cb00308e55b44a93e95024859e6fb892ca1e2dd1e257355acd0. 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/AUK211700008.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2232b0338fd5e3de315ee71ba9f676f15a1a746e29530d5c84a75353f684f9f6. 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/AUK211700009.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3ca598c41bf0b6166eb2d31ade4f41cd60e5f4c4e72e77f0b11bc35b5b9cc440. 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/AUK211700011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x439fb945a7516213f51869c301420899ef876c0bbb56d57a99bd339699b18ecb. 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/AUK211700012.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb49704f64b05324b103fe366bfe3a453da7218a47a8c333f7ab34a65d9451e60. 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/AUK211700003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2232b0338fd5e3de315ee71ba9f676f15a1a746e29530d5c84a75353f684f9f6. 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/AUK211700009.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3ca598c41bf0b6166eb2d31ade4f41cd60e5f4c4e72e77f0b11bc35b5b9cc440. Chain 2 (Bitcoin): anchored in block 956856 (2026-07-06T01:25:57Z), 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/AUK211700011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x439fb945a7516213f51869c301420899ef876c0bbb56d57a99bd339699b18ecb. Chain 2 (Bitcoin): anchored in block 956738 (2026-07-05T04:47:21Z), 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/AUK211700012.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x31c84e843dc92e0b90d781faaa9575cad38e7369969ef7bd8d4730c7c495fec8. 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/AUOD21100718.