Spring Security provides comprehensive security services for J2EE-based enterprise software applications. There is a particular emphasis on supporting projects built using The Spring Framework, which is the leading J2EE solution for enterprise software development. If you’re not using Spring for developing enterprise applications, we warmly encourage you to take a closer look at it. Some familiarity with Spring – and in particular dependency injection principles – will help you get up to speed with Spring Security more easily.

People use Spring Security for many reasons, but most are drawn to the project after finding the security features of J2EE’s Servlet Specification or EJB Specification lack the depth required for typical enterprise application scenarios. Whilst mentioning these standards, it’s important to recognise that they are not portable at a WAR or EAR level. Therefore, if you switch server environments, it is typically a lot of work to reconfigure your application’s security in the new target environment. Using Spring Security overcomes these problems, and also brings you dozens of other useful, customisable security features.

As you probably know two major areas of application security are “authentication” and “authorization” (or “access-control”). These are the two main areas that Spring Security targets. “Authentication” is the process of establishing a principal is who they claim to be (a “principal”generally means a user, device or some other system which can perform an action in your application). “Authorization” refers to the process of deciding whether a principal is allowed to perform an action within your application. To arrive at the point where an authorization decision is needed, the identity of the principal has already been established by the authentication process. These concepts are common, and not at all specific to Spring Security.

To get more information please get refer to:

http://static.springsource.org/spring-security/site/tutorial.html