Alfredo da Rocha Viana Filho (May 4, 1897 – February 17, 1973), better known as Pixinguinha, () was a Brazilian composer, arranger, flutist, and saxophonist born in Rio de Janeiro. He worked with Braz
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 0xe09d7a7748aeaae718be8f87c18fef73621d00cdb5c81d03ac1908c76e374fe6. 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/fc5a17eb-9777-42c2-836e-d6fea50c915a.json and https://artists.proofprofile.net/proofs/artist/fc5a17eb-9777-42c2-836e-d6fea50c915a.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 0x86b610ad1bbc0282e1484b652144d76176a4d6b377e9ffe935336159b64208fa. Chain 2 (Bitcoin): anchored in block 956891 (2026-07-06T07:16:32Z), 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/QZRUP2200123.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x556c2a00c5a58d9f992dee730c9685b48ba329d13ceec0c25931f8ea45d2fa2a. Chain 2 (Bitcoin): anchored in block 960144 (2026-07-29T21:09:47Z), 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/QZRUP2200122.
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 0x7a6c2b8d90475f8339423ad24bb98d2bb1536507fc1c352793068cba4a2e5173. Chain 2 (Bitcoin): anchored in block 960138 (2026-07-29T19:35:34Z), 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/QZRUP2200124.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x05b69bc8f2a2c510010507d3dd4de2b5d1f9c6f3c82fa4667e14c0135b0ae97c. 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/GBPCP1400012.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4e9358398c61033bea058a334133d652471f3347afe450b183f314e709a648de. Chain 2 (Bitcoin): anchored in block 956312 (2026-07-02T05:09:12Z), 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/USSM10302467.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x77a9e16120fa618dadca10d56522c9ad9031efbd991d866ca859a9a6d6814e35. 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/USSM10302470.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x618ab967266521f1407410fb34a4dd33b598299f43e76ec6fbe26bff0a7cc38f. 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/CA5KR1943108.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x44805d4a74b43717e935fb9b68f073736c5d93e09cd64b84a5ee48876175f1f6. 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/CA5KR1943110.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xddb3b9bfcb0108c4599c0c372aed2058c3828726ba67a4c90c4d38037fdda4a9. Chain 2 (Bitcoin): anchored in block 954130 (2026-06-17T19:07:14Z), 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/GBAYC9902431.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0a2156b5ea7ef4c88464f774a1efa33d461a398dd00f4b0a98aad1aeebcf17bd. Chain 2 (Bitcoin): anchored in block 958041 (2026-07-14T18:13:17Z), 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/GBAYC9902435.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4d5cd2d4e94180f285085b3f94130d540e42ccf67ea5373eb1a5dd292cf30114. Chain 2 (Bitcoin): anchored in block 960459 (2026-07-31T20:22:46Z), 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/CNUM71600030.