Active Directory (AD) is the implementation by Microsoft of services Directory LDAP for operating systems Windows. The main purpose of Active Directory is to provide centralized identification and authentication in a computer network system using Windows. It also allows the allocation and implementation strategies, software distribution, and installation of critical updates by administrators (Williams, 2010). Active Directory lists the elements of a network administration such as user accounts, servers, workstations, shared folders, printers, etc. A user can easily find shared resources, and administrators can control their use with features of distribution, duplication, partitioning and securing access to the resources listed. If the directors have informed the appropriate attributes, it will be possible to query the directory; for example, all color printers on this floor of the building." The Active Directory service can be implemented on Windows Server 2003 Windows 2000 Server, and Windows Server 2008, it follows the evolution of the base has flat Sat A server computer hosting the Active Directory is called domain controller. Active Directory stores its data and settings in a centralized database. The size of a basic- Active Directory can range from a few hundred objects for smaller units to several million items for large configurations. In the first documents Microsoft mentioning its existence, Active Directory was first called NTDS (NT for directory services D or "NT Directory Services" in French). One can also still find the name in the literature covering the subject as well as some utilities like AD NTDSUTIL. EXE, for example, or the name of the database NTDS, DIT (Williams, 2010).
Authentication call to verify the identity of a person or object. People have seen several systems that can be used for server authentication, and message senders and message recipients. However, the private keys are typically housed in client machines and anyone who has access to these machines can use the keys one has installed and impersonate the legitimate user. It is, therefore, necessary for users to take security measures and use the user authentication means at their disposal of the personal computers. There are three sets of user identification, password, by using the device and biometric device. Strictly speaking, this process consists of two parts - identification and authentication. Identification - a presentation by the user of a distinctive tag identifier (Snyder, 2010). This may be a password, some kind of biometric information, such as a fingerprint, a personal electronic key or smart card, etc. Authentication - a procedure that checks whether the user ID of the charges with the right to access the resource. These procedures are inextricably linked, as a way to test determines how and what one must bring to the system to gain access.
If the IT department does not take significant efforts, the number of passwords to remember as a normal user can reach 5-6. This leads to a situation where users write passwords ...