Carmelita Madriaga, known as Carmen Costa, (5 July 1920 – 25 April 2007) was a Brazilian singer and composer. Biography Born in Trajano de Moraes, in the state of Rio de Janeiro, Carmen Costa moved t
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 0x14d5c55fb97ccf45c2a9e21f083a23cd2968c07682273395f264134ea1cd3e68. Chain 2 (Bitcoin): anchored in block 953697 (2026-06-14T21:49:28Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/5bdd6d02-b358-40f3-8433-432c1447e7b2.json and https://artists.proofprofile.net/proofs/artist/5bdd6d02-b358-40f3-8433-432c1447e7b2.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 0xb6b6723fc20f51f64f5289540d5fcc4bcee4a5942314e6859f3468a73cb0e82d. Chain 2 (Bitcoin): anchored in block 956776 (2026-07-05T10:59:37Z), 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/BRBMG6100046.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8b94cb5a8271813d1c4a715ce151497f89e10caa9131f6abfddf0625845dae8f. Chain 2 (Bitcoin): anchored in block 956772 (2026-07-05T10:01:46Z), 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/BRBMG5800037.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8b94cb5a8271813d1c4a715ce151497f89e10caa9131f6abfddf0625845dae8f. Chain 2 (Bitcoin): anchored in block 957819 (2026-07-13T07:53:33Z), 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/BRBMG5800037.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe53b4b0d1c1fef0e53774b5f8dac8ec9c7ac8d5cfee8af2f2aeb5ed7c7806f17. 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/BRBMG6100072.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb6b6723fc20f51f64f5289540d5fcc4bcee4a5942314e6859f3468a73cb0e82d. 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/BRBMG6100046.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe53b4b0d1c1fef0e53774b5f8dac8ec9c7ac8d5cfee8af2f2aeb5ed7c7806f17. 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/BRBMG6100072.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc3572663bc843fcb724a34cbe8b4db9bd9a1e73bce9090fa675a4027a1035001. Chain 2 (Bitcoin): anchored in block 960250 (2026-07-30T11:13:28Z), 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/BRVWD1700410.
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 0x1c315b9527d1eea981b45d94ad9f579a712939316f4c2c83712417fd366e4564. 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/QM6MZ1497672.