The biometric is the science that permits to identify an individual automatically while taking his physiological features or compartmentalizes as the face, the voice, the iris, the retina, the inch, the shape of the hand and the ear, the DNA, or the signature, the manner to walk as a basis or to hit on a keyboard.

1.1. The state of the problem:

Nowadays, the fraud is increasing in our society. Some users are capable to falsify their identity easily. It is due to the fact that systems of authentication the more used on the market are based on the conventional solution: login and password, or then they are often associated to an ID card containing information on the identity of his possessor. This last can be compromised lost easily either. Another inconvenience of the ID card is that it doesn't take the user's physical authentication, what makes it easy to copy, as a basis. It constitutes an enormous problem therefore for his users, who would like to protect their numerous flight transactions. Then, have been developed by the scientific research to face all ways of tentative malevolent, different techniques of authentication based on the user's physical features. They are more known as biometric methods. Indeed, every member of the population possesses his own biometric characteristic, in other words it is impossible to change them or to falsify them. It is necessary to also note that more and more, biometric password replaces the conventional password in all applications requiring a level raised of security.

1.2. Authentication process:

Generally, the process of authentication consists in comparing the model of entry with only the one of the identity proclaimed the process of identification on the other hand consists in comparing a characteristic or (model) of an user with other equivalent models already stocked in a basis of data, under different stages:

1. Acquirement: This stage requires a system of acquirement equipped of a sensor in order to record the user's specific characteristic, for example: a camera, a microphone or a scanner (to see the photo)...

2. Extraction: After having kept a picture or a voice in entry a stage of segmentation permits to extract the characteristic of which the process of authentication has need. For example: to extract the face of the bottom,...

 

3. Classification: While examining models stocked in the data base, the system collects a certain number of models that looks the more like the one of the person to identify and create a list that will serve like support for the comparison of it.

4. Decision: It is the ultimate stage of this process that consists in examining models kept by a human agent and therefore to decide if the user can reach a computer for example or not.