Research And Implementation On Protecting Java Class Files

The compiled Java class file is not really binary; instead, it's just a kind of in-between code. This makes it possible for the hackers to decompile the Java class file, and in fact the decompiled file is almost the original. Thus, the hackers can easily steal the source code and some important algorithms. So it's hard to protect the Java application program, and there's a big issue about the security of Java class file.Recently, many researches have been done in the Java class file and virtual machine, and also many mechanisms have been proposed to protect the Java class file, they do work in some degree, such as JIT, code isolation, code obfuscation and code watermaking. However, All these mechanisms have their limitations respectively.This thesis proposed a simple and efficient mechanism to protect the Java class file on the customer end, based on the traditional ways. The new mechanism has some main features as below:(l)Employ the C++ program to encrypt and decrypt the Java class file in the customized ClassLoader, using the local decryption library called by JNI;(2)Use the customized ClassLoader to load the decrypted class file instead of the default j ava virtual machine.Presently, Java has been widely used in the Web application programming, but little is done to protect the Java class file. This thesis described a novel method to protect the Java class files in the customer side Web application programs. The new method employs a brand new mechanism to separate the Servlet's interface and implement: the interface remains not encrypted, and part of the implement codes will be transferred to another encryption library and encrypted; this makes the Web application program has the same security level as the local program.