Karpov (masculine, ) or Karpova (feminine, ) is a Russian surname of the Karpov family. Notable people with the surname include: Aleksandr Karpov (1917–1944), Soviet ace, double Hero of the Soviet U
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 0x1f749408059d73c8030988fe2119e3cfebc9a4ef34bc3dadfa570f167f731792. Chain 2 (Bitcoin): anchored in block 953617 (2026-06-14T09:00:45Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/1bc8d1d6-f039-4d20-a57c-36af0ff600c1.json and https://artists.proofprofile.net/proofs/artist/1bc8d1d6-f039-4d20-a57c-36af0ff600c1.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 0xa4b0f2f73ce574f725191696695b0272881a0ddddba7646fa3b240bdb4e64d25. 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/GBMA22375079.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2b8ca84c3a1b8b08eb4a5b210455098dce286c9236543a77278d4d2d8d3f28d2. Chain 2 (Bitcoin): anchored in block 957770 (2026-07-12T23:17:00Z), 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/GBMA22375080.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb67180b3db21d9cfe6803fee854caf102dd3a795b3eeeb2c254d0941f34191cd. Chain 2 (Bitcoin): anchored in block 957770 (2026-07-12T23:17:00Z), 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/GBMA22375081.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd37dda62c339eab66b93022486793bd2d3c39e00eacf4cca8ec6a7ac2ccd1821. Chain 2 (Bitcoin): anchored in block 957770 (2026-07-12T23:17:00Z), 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/GBMA22375084.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2afa5de6d1e4a9d9f62bd460f2d4d7008c5bfc3fe050213771b82a947a652d50. Chain 2 (Bitcoin): anchored in block 957770 (2026-07-12T23:17:00Z), 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/GBMA22375085.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb0f55c52312c11830784358745f9dff1efe173dde9af851b5e439c92d4fec931. Chain 2 (Bitcoin): anchored in block 957770 (2026-07-12T23:17:00Z), 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/GBMA22375087.