Follow along as Java architect Abhijit Belapurkar leads this detailed, behind-the-scenes introduction to two distinctly different (yet related) models of authorization: the code-centric model of the Java 2 platform security architecture and the user-centric model of the Java Authentication and Authorization Service.

In this tutorial, you'll employ the open standard Bouncy Castle to encrypt mobile MIDlet applications. The tutorial provides an overview of how to encrypt application-related data in a Java 2 Micro Edition (J2ME) application. It begins with a brief introduction to data encryption, then continues on to introduce the open source obfuscator, ProGuard. The final section in this tutorial compares MIDlet JAR file sizes, with and without obfuscation.

A core requirement of any non-trivial P2P application is secure communication between peers. While the details of the security depend on how the application will be used and on what it will protect, it's often possible to implement strong, general-purpose security using off-the-shelf technology such as SSL. This article demonstrates how to use SSL (via JSSE) in P2P security.

Weblets are Java programs that run in a browser, using DirectDOM to directly manipulate displayed documents. Like most Web-based programs, weblets pose a threat to system security if they're mishandled. Fortunately, weblets come with built-in security in the form of the Java sandbox. This final installment of a three-part series on DirectDOM and weblet-based development shows you how to use the sandbox to your best advantage. With simple, working examples, this article demonstrates what a weblet can and can't do by default, and also shows you how to get around the constraints of the sandbox when the situation calls for it.

The problem of system security starts with discovering the identity of the user on the other end of the communications link. This article discusses three familiar approaches for identifying users, highlights their strengths and weaknesses (alone and in combinations), and provides some examples of each.