JCloak post-processes Java^tm bytecode, encrypting the symbol information to reduce the likelihood of reverse engineering.

Java program symbol references are resolved by name, and every method, field, and class in your Java program has a fully qualified name stored in your Java class files. When your Java class references a method, the Java Virtual Machine uses the fully qualified name of the method to locate the class containing the method and the method itself. JCloak encrypts these names without preventing the VM from running your program.

Features

• New Project Wizard - Using JCloak's new project wizard you can quickly configure your initial project. The wizard performs up-front analysis of the classes determining many of the correct obfuscation settings for you. There is no need to work with complicated rules.

• Dead-code removal - Java class files are often overweight: they can contain unnecessary symbolic names for constants, unused class names, etc. JCloak trims the fat, cleaning up the class files. JCloak can also scan your Applet's references including only those classes required by the Applet, and even remove unused methods from third-party libraries your Applet may use.

• Support for Executeable JAR Files - The Java 2 runtime installation (JRE) enables Windows and Solaris^tm users to execute a Java program by double clicking the Jar file. JCloak provides full support for this feature, generating executeable Jar files from your program and packaging all the class even from third-party libraries together as one executeable Jar. 

• Obfuscates Applets, Applications, Class libraries, Servlets, Beans - JCloak automatically recognizes the type of program you are obfuscating and determines the proper settings for Applets, Applications and Servlets.  Using powerful pattern matching directives you can specify exclusion patterns to control the obfuscation of any Java code.

• Support for Java 2 - JCloak runs under Java 2 and supports obfuscation of classes for the Java 2 VM.  This includes support for inner-classes and classes compiled for Java 2 only (using 'javac -target 1.2').

• Automatic support for new JDK^tm 1.1 ".class primitive" - This primitive is described in the Java Language Specification Appendix D. JCloak detects use of this primitive and automatically adjusts the results to match the class renaming.

• Support for automatically renaming ResourceBundles - JCloak detects properties files and ResourceBundle derived classes and renames them to match the obfuscated class name.  To take advantage of this feature you must reference your ResourceBundle using the .class primitive to form the class name.  For example:  ResourceBundle myResources = getBundle(MyClass.class.getName());

• Automatic inclusion of resources - JCloak can be instructed to search for resources (non-class files with matching extensions) in a specified set of sub-directories from each package's base path.  For example if you include a .gif file resource using the class loader as follows
    Class cl = MyPanel.class;
  ImageIcon anIcon = new ImageIcon(cl.getResource("images/myicon.gif"));
  JCloak will automatically include the myicon.gif in the correct place in the output classes to allow the class loader to find and load the resource.

The Obfuscation Process

Obfuscation, simply put, is the process by which JCloak encrypts the symbol information for all internal references while leaving external references unchanged, whereas

1)Internal references

include inter-class or intra-class references to methods, fields or classes that are wholly contained within your application

2)External references

references to methods, fields or classes defined by classes outside of your application (third party package libraries or the Java virtual machine classes). Also included are methods, fields or classes defined by your application that may themselves be referenced by classes outside of your application (either directly or via overriding a method of a class defined outside of your application)