Spoof Detection Schemes

Abstract

Biometrics is defined as an automated method of verifying or recognizing the identity of a living person based on physiological or behavioral characteristics [1]. While much research has been done both to determine which traits can differentiate humans and to optimize that differentiation, the problem of determining if the presented trait originates from a living person has received relatively less attention. Between acquiring biometric data and delivering a result, there are various points where the overall security of a biometric access system can be compromised. The information flow of a biometric access system is simple (see Fig. 1). First the biometric is presented to the sensor by the person requesting access. A camera may capture a face or iris, a sensor may capture a fingerprint, a microphone may capture a voice; in each case, the raw biometric information is acquired and sent to the biometric feature extractor. The extractor is generally software that extracts the features important for determining identity from the raw information. For a fingerprint, this might be the minutiae points and for a face this could be the distance between the eyes. This extracted feature information is called a template. The template is then sent to the matcher. The matcher compares the newly-presented biometric information to previously submitted template information to make a decision. Presented along with a pin number or access card, the template may be matched against that of a single enrolled user for verification. Alternatively, it may be compared to all enrolled users for identification.