Abstract

Biometrics-based techniques have emerged as the most promising options for recognizing individuals in recent years [1]. Instead of authenticating people and granting them access to physical and virtual domains based on passwords, PINs, smart cards, keys, tokens, and so forth, these methods examine an individual’s physiological and/or behavioral characteristics in order to determine and/or ascertain his identity. Passwords and PINs are hard to remember, easy to forget, and can be guessed or stolen; cards and tokens can be misplaced, forgotten, or duplicated; cards with magnetic strips can become corrupted and unreadable. However, an individual’s biological traits cannot be misplaced, forgotten, stolen, or forged, and thus, they provide a more secure and reliable means of authentication than the traditional methods [2]. Commonly used biometrics include face, fingerprints, iris, hand geometry, voiceprint (physical traits), gait, signature, and keystroke dynamics (behavioral traits), some sample images of which are being shown in Figure 8.1.