Rodrigo Cerqueira de Souza Machado Vieira (born 1981), better known by his stage name MC Marechal or simply Marechal, is a Brazilian rapper and composer. He is considered to be a pioneer in the Brazil
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 0x6bf55e8d31ddf86f98d982f61d4a82c7c987b11d9bb682707023c487bc8c7afe. 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/76d22e6c-0d94-4dc5-b6f3-4da57f6aa150.json and https://artists.proofprofile.net/proofs/artist/76d22e6c-0d94-4dc5-b6f3-4da57f6aa150.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 0x81f0a132f73f46b55421c5acf1ee37572427ac5d865db892fcbedd0b39ee8eba. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/BXGPM2300001.
O Que Separa os Homens dos Meninos, Vol. 1
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9619b08a8fe3fd2e22af6bc9542bdbfd41ae74d9b315b1bb71c346e92cf8a2bd. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/BRDQ21600002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x23ac957de10bed271ee73590a33abc91ce742156754487929fcf91dabf18eebe. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/BRDQ21600005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe73f9627b7a49410f961bd1eb7cab732b072c848884f2fbcf45edf3c17b7f799. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/BRDQ21600004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5f446ca51c319e75c0731d1122b5f948da3e05735244964e25200f95ddad344d. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/BRX6F1400011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x44f2733f1276a6e8d35c0601ff52bb31f299e471e6994a9c3f5fccdbc9c6c238. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/BRDQ21600006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf41879f4763e91401f06e7719dacdfb51a40448a22d81b6cad3c5f7ac1a85659. 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/BRSME0600085.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2c4101e6a1651b8a55ec2785c64841be98c79f3d086b35dda91790d834d50f5c. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/BRRGE2401279.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4e98d779e59c405553c84b27cb6497c2e2beb867f8e7ee01bdd69b58c3e7d654. 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/BRM300700014.