Defining classification thresholds in template protection systems

A method of authentication of a physical object in a biometric template protection system for use in plurality of applications, the method comprising acts of;

• obtaining a first property set from biometric data associated with said physical object and helper data generated during enrolment of the physical object;
• generating a second property set by performing a noise compensating mapping on said first property set;
• determining a second number of symbol errors in said first property set;
• and
• rejecting authentication if said second number of symbol errors in said first property set is greater than a predetermined threshold, the threshold is predetermined to achieve a desired trade-off between a false accept rate (FAR) and a false reject rate (FRR) for one of the plurality of applications,
• wherein the performed noise compensating mapping is selected during enrolment of the physical object for correcting a maximum number of symbol errors equal to or greater than said predetermined threshold.

An apparatus for authentication of a physical object in a biometric template protection system for use in a plurality of applications, the apparatus comprising:

• a decoder for obtaining a first property set from biometric data associated with said physical object and helper data generated during enrolment of the physical object;
• generating a second property set by performing a noise compensating mapping on said first property set;
• and
• a processor for
• determining a second number of symbol errors in said first property set;
• and
• rejecting authentication if said second number of symbol errors in said first property set is greater than a predetermined threshold, the threshold is predetermined to achieve a desired trade-off between a false accept rate (FAR) and a false reject rate (FRR) for one of the plurality of applications,
• wherein the performed noise compensating mapping is selected during enrolment of the physical object for correcting a maximum number of symbol errors equal to or greater than said predetermined threshold.