This week we covered biometric access control systems and the many, like millions, of different ways you can implement them. Biometrics is a method of establishing a person’s identity based on chemical, behavioral, or physical attributes of that person, and is relevant in large-scale identity management across a wide range of applications. One of the most common uses for biometrics is providing access control for restricted facilities, areas, or equipment. In addition, this technology can be implemented to regulate access among computer networks, financial transactions, or transportation systems. The main purpose of biometrics in these applications is to determine or verify someone’s identity in order to prevent unauthorized people from accessing protected resources. Unlike password-based systems or access card systems, which rely on information that can be forgotten or items that can be lost, biometrics techniques provide access based on who people are rather than what they have in their possession. In principle, a biometric system is a pattern recognition unit that gathers a specific type of biometric data from a person, focuses on a relevant feature of that data, compares that feature to a preset group of attributes in its database, and then performs an action based on the accuracy of the comparison. There are a variety of characteristics that can be used for biometric comparisons, such as fingerprints, irises, hand geometries, voice patterns, or DNA information, and although there are certain limitations to biometric capabilities, an effective system can precisely identify an individual based on these factors. A standard biometric access control system is composed of four main types of components: a sensor device, a quality assessment unit, a feature comparison and matching unit, and a database.  Unlike password based system there is a start-up cost associated with these types of systems and they can very from moderately inexpensive to impressively expensive.