Biometric system
View Patent ↗A biometric system for obtaining a biometric enrolment measurement is described. The system comprises a biometric capture unit for capturing biometric data from a user and a control means for producing a biometric match template there from. The control means also analyses the template to determine if the enrolment measurement may be susceptible to allowing false acceptances when in use. This is achieved by using the match template to verify against a number test templates, which have been created from earlier acquired biometric measurements, of the same class, obtained from other sources. If one or more false accepts are detected the enrolment measurement may be rejected.
1. A biometric system comprising:
a biometric capture unit operative to capture a biometric data sample comprising a biometric measurement from a user; and
control means operative to produce a reference biometric template from the biometric data sample, the reference biometric template comprising a set of biometric reference data used to authenticate the biometric data sample read from the user, the control means being further operative to validate the template, validation comprising performing a plurality of test authentication each test authentication comprising using the template for attempted authentication of one of a plurality of known invalid biometric data samples, validation of the biometric template failing if the test authentications indicate greater than a predetermined susceptibility to false acceptances and succeeding if the test authentications do not so indicate.
2. A biometric system as claimed in claim 1 , wherein the biometric capture unit comprises a fingerprint capture unit.
3. A biometric system as claimed in claim 1 , wherein the biometric data sample is examined to identify the classification of the biological feature from which it was taken, and wherein known invalid data samples taken from biological features belonging to the same classification are used for validation of the reference template.
4. A biometric system as claimed in claim 1 , wherein validation is based upon the number of acceptances returned from test authentications using the reference template for authentication of each of the plurality of known invalid data samples.
5. A biometric system as claimed in claim 1 , further comprising user interface means arranged to inform the user if the measurement is not acceptable, wherein the biometric data capture unit is operative to capture a new biometric data sample from the user and the control unit is operative to validate a new reference template based on the new data sample, new samples being captured and validated successful validation is achieved.
6. A biometric system as claimed in claim 5 , wherein the user interface means provides a visual indication to the user as to whether or not the biometric capture was successful.
7. A biometric system as claimed in claim 6 , wherein the visual indication comprises a colored light.
8. A biometric system as claimed in claim 5 , wherein the user interface comprises one or more light emitting diodes (LEDs) located adjacent the biometric capture unit and wherein one or more of the LEDs are illuminated in such a way as to provide the user with feedback regarding the capture of the user's fingerprint.
9. A method of obtaining a biometric enrolment measurement from a user, the method comprising:
capturing a biometric measurement from a user, by a biometric capture unit;
producing a reference biometric template therefrom, the reference biometric template comprising a set of reference biometric data, by a processor
storing the reference biometric template in a memory accessible by a processor; and
validating the reference template, validation comprising performing a plurality of test authentications, each test authentication comprising using the reference template for attempted authentication of one of a plurality of known invalid reference data samples;
determining that the reference template is invalid and that validation has failed if the test authentications indicate greater than a predetermined susceptibility to false acceptances, and that validation has succeeded if the test authentications do not so indicate, by the processor.
10. A method a claimed in claim 9 , wherein the biometric measurement is obtained from a fingerprint.
11. A method as claimed in claim 9 , wherein the biometric measurement is examined to identify a classification of the biological feature from which it was taken, and wherein known invalid data samples taken from features belonging to the same classification are used for validation of the reference template.
12. A method as claimed in claim 9 , wherein validation is based upon the number of acceptances resulting from use of the reference template for authentication of the plurality of known invalid data samples.
13. A method as claimed in claim 9 , further comprising the steps of:
upon a validation failure and until a successful validation is achieved;
informing the user that the validation failed;
capturing a new biometric data sample from the user, by the biometric capture unit;
creating a new reference template based on the new data sample; and
performing validation on the new reference template.
14. A method as claimed in claim 13 , wherein a visual indication is provided to the user as to whether or not the biometric capture was successful.
15. A method as claimed in claim 14 , wherein the visual indication is a colored light or an on screen indication including, at least, one of text, animation or graphic.
16. A computer readable medium stoma a program of instructions executable by a processor, the program of instructions controlling the processor so as to perform the steps of:
directing a biometric capture unit to capture a biometric measurement for a user;
producing a reference biometric template therefrom, the reference biometric template comprising a set of reference biometric data;
storing the reference biometric template in a memory accessible by the processor; and
validating the reference template, validation comprising performing a plurality of test authentications, each test authentication comprising using the reference template for attempted authentication of one of a plurality of known invalid reference data samples; and
determining that the reference template is invalid and that validation has failed if the test authentications indicate greater than a predetermined susceptibility to false acceptances, and that validation has succeeded if the test authentications do not so indicate.
17. A computer readable medium as claimed in claim 16 , wherein the biometric measurement is, at least one of, a fingerprint, voice print, facial image, iris scan or finger geometry.
18. A computer readable medium as claimed in claim 16 , wherein the biometric measurement is examined to identify a classification of a biological feature from which it was taken, and wherein known invalid data samples taken from features belonging to the same classification are used for validation of the reference template.
19. A computer program as claimed in claim 16 , wherein validation is based upon the number of acceptances returned from use of the reference template for authentication of the plurality of known invalid data samples.
20. A computer readable medium as claimed in claim 16 , wherein the stored instructions comprise instructions controlling the processor to perform the steps of:
upon a validation failure and until a successful validation is achieved;
informing the user that the validation failed;
capturing a new biometric data sample from the user, by the biometric capture unit;
creating a new reference template based on the new data sample; and
validating the new reference template.
21. A computer program as claimed in claim 20 , wherein a visual indication is provided to the user as to whether or not the biometric capture was successful.
22. A computer program as claimed in claim 21 , wherein the visual indication comprises a colored light or on screen prompt.
23. A biometric system as claimed in claim 1 , wherein a score is computed for each comparison of the reference sample with one of the plurality of known invalid data samples and wherein validation is based on an average score resulting from use of the reference template in authentication of the plurality of known invalid data samples.
24. A method as claimed in claim 9 , wherein a score is computed for each comparison of the reference sample with one of the plurality of known invalid data samples and wherein validation is based on an average score resulting from use of the reference template in authentication of the plurality of known invalid data samples.
25. A computer readable medium as claimed in claim 16 , wherein a score is computed for each comparison of the reference sample with one of the plurality of known invalid data samples and wherein validation is based on an average score resulting from use of the reference template in authentication of the plurality of known invalid data samples.