The Java 2 Standard Edition discussion on security can be viewed from http://java.sun.com/j2se/1.5.0/docs/guide/security/index.html.
The chapter titled Security in the Java EE 5 Tutorial.
The Administration Guide chapter titled Chapter 9, Configuring Message Security.
The chapter titled Chapter 5, Securing Applications, in Sun Java System Application Server Platform Edition 9 Developer’s Guide in the Developer's Guide.