Wireless biometric authentication system and method

1. A method comprising:

obtaining, by an access device, a second biometric sample of a user;

generating, by the access device, a second biometric template from the second biometric sample;

for each mobile device of a plurality of mobile devices within a proximate vicinity of the access device, the plurality of mobile devices comprising a first mobile device:

retrieving, by the access device, a public value of the mobile device, wherein:

the public value of the mobile device and a private value of the mobile device were generated by passing a first biometric template of the mobile device to a first function of a fuzzy extractor; and

the first biometric template of the mobile device was generated from a first biometric sample of the mobile device;

generating, by the access device, a secret cryptographic key by passing the second biometric template and the public value of the mobile device to a second function of the fuzzy extractor;

encrypting, by the access device, the second biometric template with the secret cryptographic key; and

broadcasting, by the access device, the encrypted second biometric template, wherein the encrypted second biometric template is received by the plurality of mobile devices;

receiving, by the access device and from the first mobile device, a confirmation of a match between the second biometric template and a first biometric template of the first mobile device after the first mobile device decrypts the encrypted second biometric template and compares the decrypted second biometric template to the first biometric template, wherein the first biometric template of the first mobile device is generated from a first biometric sample of the first mobile device; and

responsive to the confirmation, conducting a transaction between the access device and the first mobile device.

2. The method of claim 1 :

wherein generating the second biometric template from the second biometric sample comprises generating a second small biometric template and a second large biometric template;

wherein the public value of the mobile device that was generated by passing the first biometric template of the mobile device to the first function of the fuzzy extractor was generated by passing a first small biometric template of the mobile device to the first function of the fuzzy extractor;

wherein the first small biometric template of the mobile device was generated from the first biometric sample of the mobile device;

wherein generating the secret cryptographic key by passing the second biometric template and the public value of the mobile device to the second function of the fuzzy extractor comprises generating the secret cryptographic key by passing the second small biometric template and the public value of the mobile device to the second function of the fuzzy extractor;

wherein encrypting the second biometric template with the secret cryptographic key comprises encrypting the second large biometric template with the secret cryptographic key;

wherein broadcasting the encrypted second biometric template to the plurality of mobile devices comprises broadcasting the encrypted second large biometric template to the mobile device of the plurality of mobile devices;

wherein the match is between the second large biometric template and a first large biometric template of the first mobile device; and

wherein the first large biometric template of the first mobile device is generated from the first biometric sample of the first mobile device.

3. The method of claim 2 , wherein the second small biometric template is one of:

an obfuscated copy of the second large biometric template; and

an incomplete copy of the second large biometric template.

4. The method of claim 2 , wherein generating the first large biometric template from the second biometric sample comprises:

extracting one or more distinct characteristics from the second biometric sample; and

generating a digital reference of the one or more distinct characteristics.

5. The method of claim 2 , wherein subsequent to receiving the encrypted second large biometric template from the access device, the first mobile device:

attempts to decrypt the encrypted second large biometric template with a secret cryptographic key of the first mobile device, wherein the secret cryptographic key of the first mobile device was generated by passing a first small biometric template of the first mobile device to the first function of the fuzzy extractor, wherein the first small biometric template of the first mobile device was generated from the first biometric sample of the first mobile device;

responsive to decrypting the encrypted second large biometric template, determines whether the second large biometric template matches the first large biometric template of the first mobile device; and

responsive to determining that the second large biometric template matches the first large biometric template of the first mobile device, sends the confirmation of the match to the access device.

6. The method of claim 5 :

wherein the plurality of mobile devices comprises a second mobile device; and

wherein subsequent to receiving the encrypted second large biometric template from the access device, the second mobile device attempts unsuccessfully to decrypt the encrypted second large biometric template with a secret cryptographic key of the second mobile device;

wherein the secret cryptographic key of the second mobile device was generated by passing a first small biometric template of the second mobile device to the first function of the fuzzy extractor; and

wherein the first small biometric template of the second mobile device was generated from a first biometric sample of a different user.

7. The method of claim 5 , wherein a similarity between the second small biometric template and the first small biometric template of the first mobile device exceeds a threshold matching score.

8. The method of claim 2 , wherein prior to obtaining the second biometric sample of the user, the method further comprises:

broadcasting a transmitting station identifier to each of the plurality of mobile devices; and

for each of the plurality of mobile devices:

receiving from the mobile device, the public value of the mobile device and storing the public value of the mobile device.

9. The method of claim 2 wherein obtaining the second biometric sample of the user comprises one of:

taking a photographic image of the user's face;

taking a fingerprint of the user;

taking a voice sample of the user;

taking a DNA sample of the user;

taking a retinal scan of the user; and

taking a hair sample of the user.

10. An access device comprising:

a processor; and

a computer readable medium comprising code, executable by the processor, for implementing a method comprising:

obtaining a second biometric sample of a user;

generating a second biometric template from the second biometric sample;

for each mobile device of a plurality of mobile devices within a proximate vicinity of the access device, the plurality of mobile devices comprising a first mobile device:

retrieving a public value of the mobile device, wherein:

the public value of the mobile device and a private value of the mobile device were generated by passing a first biometric template of the mobile device to a first function of a fuzzy extractor; and

the first biometric template of the mobile device was generated from a first biometric sample of the mobile device;

generating a secret cryptographic key by passing the second biometric template and the public value of the mobile device to a second function of the fuzzy extractor;

encrypting the second biometric template with the secret cryptographic key; and

broadcasting the encrypted second biometric template to the mobile device in the plurality of mobile devices;

receiving, from the first mobile device, a confirmation of a match between the second biometric template and a first biometric template of the first mobile device after the first mobile device decrypts the encrypted second biometric template and compares the decrypted second biometric template to the first biometric template, wherein the first biometric template of the first mobile device is generated from a first biometric sample of the first mobile device; and

responsive to the confirmation, conducting a transaction between the access device and the first mobile device.

11. The access device of claim 10 ,

wherein generating the second biometric template from the second biometric sample comprises generating a second small biometric template and a second large biometric template;

wherein the public value of the mobile device that was generated by passing the first biometric template of the mobile device to the first function of the fuzzy extractor was generated by passing a first small biometric template of the mobile device to the first function of the fuzzy extractor;

wherein the first small biometric template of the mobile device was generated from the first biometric sample of the mobile device;

wherein generating the secret cryptographic key by passing the second biometric template and the public value of the mobile device to the second function of the fuzzy extractor comprises generating the secret cryptographic key by passing the second small biometric template and the public value of the mobile device to the second function of the fuzzy extractor;

wherein encrypting the second biometric template with the secret cryptographic key comprises encrypting the second large biometric template with the secret cryptographic key;

wherein broadcasting the encrypted second biometric template to the plurality of mobile devices comprises broadcasting the encrypted second large biometric template to the mobile device of the plurality of mobile devices;

wherein the match is between the second large biometric template and a large first biometric template of the first mobile device; and

wherein the first large biometric template of the first mobile device is generated from the first biometric sample of the first mobile device.

12. The access device of claim 11 , wherein the second small biometric template is one of.

an obfuscated copy of the second large biometric template; and

an incomplete copy of the second large biometric template.

13. The access device of claim 11 , wherein generating the second large biometric template from the second biometric sample comprises:

extracting one or more distinct characteristics from the second biometric sample; and

generating a digital reference of the one or more distinct characteristics.

14. The access device of claim 11 , wherein subsequent to receiving the encrypted second large biometric template from the access device, the first mobile device:

attempts to decrypt the encrypted second large biometric template with a secret cryptographic key of the first mobile device, wherein the secret cryptographic key of the first mobile device was generated by passing a first small biometric template of the first mobile device to the first function of the fuzzy extractor, wherein the first small biometric template of the first mobile device was generated from the first biometric sample of the first mobile device;

responsive to decrypting the encrypted second large biometric template, determines whether the first second large biometric template matches the first large biometric template of the first mobile device; and

responsive o determining that the first second large biometric template matches the first large biometric template of the first mobile device, sends the confirmation of the match to the access device.

15. The access device of claim 14 :

wherein the plurality of mobile devices comprises a second mobile device; and

wherein subsequent to receiving the encrypted second large biometric template from the access device, the second mobile device attempts unsuccessfully to decrypt the encrypted second large biometric template with a secret cryptographic key of the second mobile device;

wherein the secret cryptographic key of the second mobile device was generated by passing a first small biometric template of the second mobile device to the first function of the fuzzy extractor; and

wherein the first small biometric template of the second mobile device was generated from a first biometric sample of a different user.

16. The access device of claim 14 , wherein a similarity between the second biometric template and the first small biometric template of the first mobile device exceeds a threshold matching score.

17. The access device of claim 11 , further comprising:

broadcasting a transmitting station identifier to each of the plurality of mobile devices; and

for each of the plurality of mobile devices:

receiving from the mobile device, the public value of the mobile device and storing the public value of the mobile device.

18. The access device of claim 11 , wherein obtaining the second biometric sample of the user comprises one of:

taking a photographic image of the user's face;

taking a fingerprint of the user;

taking a voice sample of the user;

taking a DNA sample of the user;

taking a retinal scan of the user; and

taking a hair sample of the user.