With this latest 1.4 release, you'll find many enhancements in the security architecture. Several features that were previously available separately are now part of the core API set. These include support for encryption and decryption with the Java Cryptography Extension (JCE), support for Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols with the Java Secure Socket Extension (JSSE), and support for user-based authentication and access controls with the Java Authentication and Authorization Service (JAAS). In addition to the inclusion of these previously optional packages, you'll find new support for building and verifying certificate chains with the Java Certification Path API and support for the Kerberos V5 mechanism under Java GSS-API and JAAS. Additional enhancements were made in improving the security policy-managing tool, policytool, and in adding support for dynamically loading security policies.
The following article introduce all these features and examine them in more detail. Click here to read the full article.
Source: Sun