Java Cryptography

About the Examples

Versions

The examples in this book run with the Java Developer’s Kit (JDK) 1.2 and the Java Cryptography Extension (JCE) 1.2. The examples in the book were tested with JDK 1.2beta3 and JCE 1.2ea2. Some of the topics covered are applicable to JDK 1.1, especially the Identity-based key management discussed in Chapter 5 and the MessageDigest and Signature classes in Chapter 6. However, anything involving encryption requires the JCE. The only supported version of the JCE is 1.2, and it only runs with JDK 1.2. (Although the JCE had a 1.1 release, it never progressed beyond the early access stage. It is not supported by Sun and not available from their web site any longer.)

The signed applets in Chapter 8 work with HotJava 1.1, Netscape Navigator 4.0, and Internet Explorer 4.0.

File Naming

This book assumes you are comfortable programming in Java and familiar with the concepts of packages and CLASSPATH. The source code for examples in this book should be saved in files based on the class name. For example, consider the following code:

import java.applet.*;
import java.awt.*;

public class PrivilegedRenegade extends Applet {

  ...

}

This file describes the PrivilegedRenegade class; therefore, you should save it in a file named PrivilegedRenegade.java.

Other classes belong to particular packages. For example, here is the beginning of one of the classes from Chapter 9:

package oreilly.jonathan.security; import java.math.BigInteger; import java.security.*; public class ElGamalKeyPairGenerator ...