María Luisa Landín (9 October 1921 – 20 June 2014) was a Mexican singer. She sang bolero, Latin ballad and mariachi styles and was most noted for bolero. She began her career singing as a duo with her
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 0x6a5f87b41554881ffd4227b1b82f4819d36c040bb9a023fc3dfb5915b94d1b62. Chain 2 (Bitcoin): anchored in block 954342 (2026-06-19T03:22:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/8a7fa772-7164-41b4-a6e3-58aacf0f7744.json and https://artists.proofprofile.net/proofs/artist/8a7fa772-7164-41b4-a6e3-58aacf0f7744.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 0xf0d7971c514644a1813aa511d24047f7023c67c3edbefd217b5c07464c9477ff. Chain 2 (Bitcoin): anchored in block 956889 (2026-07-06T06:56:49Z), 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/QM7281417920.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x079b40ebdce8a646b34e8ac1cd6ac4cc282769378c30970e27db23cc70fa3022. Chain 2 (Bitcoin): anchored in block 958808 (2026-07-20T02:49:15Z), 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/QM7281417921.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfd96cba3c51f8f04a2a934ae306478e61ea55947a23331d9db6a8c6c31618010. Chain 2 (Bitcoin): anchored in block 958594 (2026-07-18T18:05:01Z), 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/QM7281417929.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaf8ce1b61bf6db3cc80e0de8a834cb4fe9ead0a7bafcd856a2c9529c8879f23c. Chain 2 (Bitcoin): anchored in block 958857 (2026-07-20T09:45:25Z), 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/QM7281417931.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x43b6716919e6bf63086a9634455c51f043edcb45c16ee4eac420fa10cd71129e. Chain 2 (Bitcoin): anchored in block 959088 (2026-07-22T02:14:33Z), 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/MXD941801635.