Biometrics is responsible for the identification of persons. Thus, biometrics studies the physiological and behavioral, qualities that make each person unique from other. Thanks to biometrics, it is possible to establish clear differences between two people. Biometrics had their first characteristic uses at the end of the 19th century, when it was established that fingerprints were different in every human being. At that time failed to find a method that would be used by police institutions and which is in force today. With the passage of time could find other qualities that are also unique to each individual, these are termed them biometric indicators.

The most common biometric indicators are: fingerprints, iris and retina. However, there are other indicators such as the features of the face, the voice, how to walk, talk or write. All of these indicators have gone from being used by investigative agencies, to be employed by companies of technologies for the creating the so dreamed biometric systems. Biometric systems are devices that have many utilities. In the field of security, these systems have come to be the favorite of many customers. This is because that these systems allow you to restrict access to sites or information conclusively.

Thus, biometric systems are the new paradigm for access controls. Access control is a mechanism that prevents unwanted people from entering a protected location or access to private information. First access controls were the traditional doors, then they were replaced by electronic gates which were opened by using smart cards. While these cards were a breakthrough, their effectiveness was affected by unscrupulous people, who found the way to falsify them, steal them or simply individuals who lend them to others.