Authentication server

An authentication server contains a database of user IDs, passwords, and other information such as IP addresses and permissible services.

He listens for connections from client systems via a computer network. Passwords are not stored in clear text, only their image under a one-way function, such as Message Digest Algorithm 5 (MD5 ) for Windows systems or Crypt ( a Data Encryption Standard ) method is to Unix, saved. If a user attempts to log on to a device that uses an authentication server for evaluation of credentials, encrypted, this unit user ID and password as a file and sends it to the test on the authentication server. This compares with the stored password. If they match, the stored data of the tested user are released. The disadvantage of authentication server is that these only work with systems that scan the server when a user logs on.

For authentication servers include, for example, Windows Domain Controller, Remote Authentication Dial- In User Service ( RADIUS) or Extended Single Sign -On ( XSSO ).