Systems and processes for digital identity authentication via lossless fuzzy extractors

A system comprising:

• a remote server;
• and
• a mobile device, wherein the mobile device comprises a processor and a memory, and wherein the processor is operatively configured to:
• receive a first biometric template corresponding to a subject;
• process the first biometric template, wherein processing the first biometric template comprises:
• generating a spherical domain embedding of the first biometric template;
• performing a linear transformation of the spherical domain embedding of the first biometric template, wherein the linear transformation maps the spherical domain embedding of the first biometric template to a codeword embedded in the spherical domain, and wherein the codeword corresponds to an error correcting code;
• storing a secure sketch comprising data corresponding to the linear transformation;
• and
• storing helper data comprising auxiliary data corresponding to parameters of the linear transformation;
• encrypting a secret key with the codeword to generate an encrypted secret;
• receive a second biometric template corresponding to the subject;
• process the second biometric template, wherein processing the second biometric template comprises:
• generating a spherical domain embedding of the second biometric template;
• and
• applying the secure sketch and helper data to the second biometric template to generate a reconstructed codeword;
• determine a match between the codeword and the reconstructed codeword;
• and
• access the secret key via decrypting the encrypted secret with the reconstructed codeword.

A non-transitory computer readable medium comprising instructions that, when read by a processor, cause the processor to perform:

• receiving a first biometric template corresponding to a subject;
• processing the first biometric template, wherein processing the first biometric template comprises:
• generating a spherical domain embedding of the first biometric template;
• performing a linear transformation of the spherical domain embedding of the first biometric template, wherein the linear transformation maps the spherical domain embedding of the first biometric template to a codeword embedded in the spherical domain, and wherein the codeword corresponds to an error correcting code;
• storing a secure sketch comprising data corresponding to the linear transformation;
• and
• storing helper data comprising auxiliary data corresponding to parameters of the linear transformation;
• encrypting a secret key with the codeword to generate an encrypted secret;
• receiving a second biometric template corresponding to the subject;
• processing the second biometric template, wherein processing the second biometric template comprises:
• generating a spherical domain embedding of the second biometric template;
• and
• applying the secure sketch and helper data to the second biometric template to generate a reconstructed codeword;
• determining a match between the codeword and the reconstructed codeword;
• and
• accessing the secret key via decrypting the encrypted secret with the reconstructed codeword.