Marcus Viana (Belo Horizonte, 3 August 1953) is a Brazilian violinist, singer, keyboardist and composer. He founded his own label Sonhos & Sons in the first half of the 1990s and is also the leader of
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 0xba17f205cd22478c097f6034c9d5d1b099d85636eec011a0b00317bfbf4b7a5d. Chain 2 (Bitcoin): anchored in block 953408 (2026-06-12T19:28:13Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/f03aa325-cb90-441d-ac11-0938d13a303f.json and https://artists.proofprofile.net/proofs/artist/f03aa325-cb90-441d-ac11-0938d13a303f.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 0x8fb46a334f343c86feeb382c224cbae85c8d3320b0ed2d5e619c5a0fe30e11bd. 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/BRSOS0200179.
Paula Fernandes Ao Vivo (Live From São Paulo / 2010)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcdf795ad60d449194a750739d14232e7a7e8320e155a0c2f6490b257e776f7ec. 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/BRUM71002509.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe261a20328198cdaffb379d1b87975994d94f143f6cd1455f8da8324a549987d. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), 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/BRSOS1500012.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6ee61dad4153a5042b7ffad49e43c018349de284d2ada0a6eadbb1ae20cf5e31. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), 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/BRSOS1500004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5e3ebaa9674f9bc485f1ddae48727021a1f56746ddb2f666d6a9c6065cecad8a. 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/BRJ051900009.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x68cd11d586acafe83ebb37651f3fe2729ea3792590f720afcf456fb00dce9561. 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/BRJ051900010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcdf795ad60d449194a750739d14232e7a7e8320e155a0c2f6490b257e776f7ec. 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/BRUM71002509.
Paula Fernandes Ao Vivo (Deluxe Edition)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcdf795ad60d449194a750739d14232e7a7e8320e155a0c2f6490b257e776f7ec. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/BRUM71002509.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9b986d267987539a9eb8246ad2f76fa468f36f1a5cc6b220a8daacfcf6fe739a. 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/BRSOS0400087.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x49bfadbcbd2f13bad1d8929cc2e04d81e10f9eaf874099c62833416bf02a8fc8. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/BRSOS0400088.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x42dfa2627a582499123a5013d7e3309aa916e2661447f4d27a705e701e790919. 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/BRSOS0400089.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2313f2dd67f1ae3fbd2bd06165220ffac557314c0639c8ea0451540fd1435502. 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/BRSOS0400090.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9a2c9c8bab8c2465942c34561871b65efd74b9d4ad611744d8e7a47e2d0c8397. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/BRSOS0200160.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa9eaebf3b4d183d4c388dfe57a43e9a93eedd0456e4e254638e686165e14f8c3. 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/BRSOS1300001.
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 0x4c4b6b67537656a285aa4a3d571b9ac5a3a392944eeae1cde51305726a2cf8f1. Chain 2 (Bitcoin): anchored in block 960500 (2026-08-01T03:13:03Z), 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/BRSOS1500005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdf58cc51dc66450eea9f67dba15d8fe6e8a6dac8b0e1e9d4f6c050a8548d4216. Chain 2 (Bitcoin): anchored in block 960117 (2026-07-29T14:28:24Z), 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/BRSOS1500007.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf54280fd5b54fe4a3e360bc122a28062b7c68641b8f74744579ff8f2d563d8b9. Chain 2 (Bitcoin): anchored in block 960403 (2026-07-31T13:04:34Z), 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/BRSOS1500003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1dee6ad1cef2c81077e0d08963ae9525649cbb598332a0e59304cc286c35c092. Chain 2 (Bitcoin): anchored in block 960254 (2026-07-30T12:06:10Z), 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/BRSOS1500015.