Kubuś (Polish for "Little Jacob") is a Polish improvised fighting vehicle used by the Home Army in the Warsaw Uprising during World War II. The single vehicle was built in secret to function as an arm
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 0x516632be63b5150a0cd342a59c58fe6589d37dde0c728c982e2bc468aab7bf6a. 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/52c5d821-da0d-4bfa-8d39-666d7da4a953.json and https://artists.proofprofile.net/proofs/artist/52c5d821-da0d-4bfa-8d39-666d7da4a953.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 0x3bd92849b33ebe5b6ecddefba460f99bcd06b5e9a7657b92cfd3723325c9c75c. Chain 2 (Bitcoin): anchored in block 958157 (2026-07-15T13:14:32Z), 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/QZDA42181905.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x38b576eb59f299a7e844166300c5018efb418751514b3de6c9f289151799af02. 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/QZMEP2186022.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0ee9d26f73519a2e829ed0d99f3dbb1a5305c73d5fd7a655abb3ef3caf003e1e. Chain 2 (Bitcoin): anchored in block 958444 (2026-07-17T19:12:23Z), 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/QZDA72224166.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe49f09ab3ed98f63aada37d5de5718191567762209f7b2c91501b07f276355ab. Chain 2 (Bitcoin): anchored in block 958300 (2026-07-16T16:14:30Z), 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/QZDA62384831.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x55fc6459bd59cfa26011f5e75ec880b061793ae495102b318aa6990589a52332. Chain 2 (Bitcoin): anchored in block 958203 (2026-07-15T21:24:46Z), 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/QZRP42202829.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x72f7e1b799bcd0df7a6face8bd9be8fcbdb06cbcc63021f751ca06c97bbe9269. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/QZNWR2117344.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6125a991cc32d5e6f1cebd7503fb113f7166046390e88cb1ebba2871ad9add3d. Chain 2 (Bitcoin): anchored in block 959100 (2026-07-22T05:29:55Z), 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/QZFYZ2267943.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1b8b20977084faf1a16eb6870168290a93a8eef4ac75669c21aa3c61167e5e2f. Chain 2 (Bitcoin): anchored in block 957613 (2026-07-11T21:37:58Z), 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/QZNWV2218213.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x29e8f5c5ccb67cd73d1d2b833093872fb7b354ba97cfff918b4d794c87b80c58. Chain 2 (Bitcoin): anchored in block 957613 (2026-07-11T21:37:58Z), 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/QZDA42124365.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc2c09775ed9f6a4f4f7e1094cb38b91e07e445c2b6f7d2d0784480879f55f214. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/QZK6Q2376947.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3d163bf6c7b9b8233d4f96d255f4358333ec0e1fa46294c7add7fb06e643aedf. Chain 2 (Bitcoin): anchored in block 958761 (2026-07-19T17:49:48Z), 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/PLC062375686.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9ab0369fc34d2a77487ecf3d729148cfabba1e15aa844110de74410a36bd87a5. Chain 2 (Bitcoin): anchored in block 958212 (2026-07-15T23:25:50Z), 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/PLC062383009.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x687a4342e25a3b17d55865fc4c07c90650d19a4208d92ec881529484e5f8afad. 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/PLC062403174.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9548873ab408e8b18aa298b79229851fa9058c37c70481a305d474913a032072. Chain 2 (Bitcoin): anchored in block 958761 (2026-07-19T17:49:48Z), 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/PLC062426742.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf3d56ec077862a1361911364f510351cd80268ced8c59df620e5f81da96dc9ac. 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/PLC062503341.