Karcer is a Polish punk rock band playing since 1982. Members 1982 Krzysztof Żeromski - guitar, vocals Piotr Dudziński Jarosław Jodłowski 1984 Krzysztof Żeromski - guitar, vocals Dariusz Lewandows
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 0xa4d239fc9d5ccf27dc4c2f829126dab7afec3c72e1b46a2c5890f43dca16b02a. Chain 2 (Bitcoin): anchored in block 953742 (2026-06-15T04:47:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a03008d1-2772-473a-a24c-a8955d172b4a.json and https://artists.proofprofile.net/proofs/artist/a03008d1-2772-473a-a24c-a8955d172b4a.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 0x09dcacc63c3de05b3454cfff4084527e0a06c71517d5c1d6bf6874de5d3c9994. 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/PLH921300104.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd57bbf882b1ea87d52cfaa627e7645d00013769865fbddb14da8cb8355d3c1ca. Chain 2 (Bitcoin): anchored in block 958601 (2026-07-18T19:27:02Z), 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/PLH921300106.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9f0ff2f9d4104cc3d06d2ce93f35b84e464bddf9aa1d563288cd330e0b69b068. Chain 2 (Bitcoin): anchored in block 959061 (2026-07-21T21:34:21Z), 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/PLH921300112.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4d75da82ef24d185468764713c0019be231c87a93bcb85a3c0f9c65d5c05ee97. Chain 2 (Bitcoin): anchored in block 958738 (2026-07-19T13:10:36Z), 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/PLH921301052.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2fc7f528cc4c93fb1cc2652f342d5ed8048a913e4622ad49f7b73a85cf6b1d75. 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/PLH921700057.