Intrinsic Failure

Intrinsic failure is the security lapse due to an incorrect decision made by the biometric system. A biometric verification system can make two types of errors in decision making, namely, false accept and false reject. A genuine (legitimate) user may be falsely rejected by the biometric system due to the large differences in the users’ stored template and input biometric feature sets. These intra-user variations may be due to incorrect interaction by the user with the biometric system (e.g., changes in pose and expression in a face image) or due to the noise introduced at the sensor (e.g., residual prints left on a fingerprint sensor). False accepts are usually caused by lack of individuality or uniqueness in the biometric trait, which can lead to large similarity between feature sets of different users (e.g., similarity in the face images of twins or siblings). Both intra-user variations and inter-user similarity may also be caused by the use of non-salient features and non-robust...