Sérgio Krakowski Costa Rego (born 18 December 1979) is a Brazilian musician best known for his work as a pandeiro player. His career is characterized by the integration of Brazilian musical traditions
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 0xcdfbf55fd07a9563f56db1e97241b6620e60f38ae572cd4d73cbfb970a13b5e0. Chain 2 (Bitcoin): anchored in block 954038 (2026-06-17T02:57:22Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/3e26659f-863d-45fe-affc-b02e82b67191.json and https://artists.proofprofile.net/proofs/artist/3e26659f-863d-45fe-affc-b02e82b67191.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Mascarada: Zé Keti por Sergio Krakowski Trio e Jards Macalé
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 0xad4a05628265dcf6cafadf55b193fe43f3a99c693cae03442a26d7ef0187a9a7. 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/NLGZ21400056.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x572a9d64c3c8c50e90a763d3a4535e8257eedc4f0d814ccad80e3655b412a57a. 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/BXUHS1700002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5f00863ca972d39a8339209dbc734646dc91e3a7f8eca2b036a1b03fe168204e. 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/BXUHS1700010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9cddf19f7b142f03eb49d6dce927d51227a944c3e3c037376f1502a106db5234. 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/NLGZ21400057.
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 0xb06877f91ef116aed41e6b99bd4257727a05bb96cd9106537216ca782f7ccd2d. Chain 2 (Bitcoin): anchored in block 960229 (2026-07-30T08:30:10Z), 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/NLGZ21400058.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x886f3a10d8a4317cb2b7b21ab3e187c1d0f527185579a705608de3507b73772e. Chain 2 (Bitcoin): anchored in block 960327 (2026-07-31T00:26:26Z), 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/NLGZ21400060.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x259a018de4e6fe69c6da0b6007925924b4fe1b9dbea6257bae1f27771c6dcf3b. 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/NLGZ21400061.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4fea161fd566f7a650720b89b9a6e2bbef11fe0871f08c82568a1c88b31af208. Chain 2 (Bitcoin): anchored in block 960264 (2026-07-30T14:36:16Z), 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/BR12P1200028.