Study And Implementation Of Java Source Code Oriented Encrypting And Dynamically Decrypting Mechanism

With the development of computer technology, Java has won its place among technicians and developmental factory owners. Java is simple,dynamic, and independent on platform. Its application to the internet especially outshines others.However, Java has built-in defects in the property right protection.In order to realize the capability of Cross-Platform, the code generates byte-code after compiling,which could be decompiled to the original source code. This severely compromises the intellectual property.The purpose of this thesis is to develop a mechanism to encrypt and dynamically decrypt the class files which contain Java source code, based on the traditional ways. It protects the source code without sacrificing the normal performance of Java software. This article combines the applications of Java Cryptography Extension, Advanced Encryption Standard,user-define classloader,Java Native Interface, and other technologies, and develops a secure, flexible, efficient Java source code oriented encrypting and dynamically decrypting solution.The security mechanism is composed of two parts: encryption and decipher.Encryption part: Use the encryption expansion provided by Java combining with the advanced encryption standard AES algorithm to encrypt Java class files which need to be encrypted, and withdraw the encryption key and then hide it in the Dynamic Link Library complied by native language.Decipher part: Through user-defined classloader, invoked the dynamic link library to load and to decipher class documents. User-defined classloader can recognize encrypted class documents and carry out the decipher operation. The usage of configuration files guarantees the system's flexibility as a whole. Hiding the key guarantees system security. This thesis applies and tests the developed mechanism of Java applications of both single machine and Web, and analyses the test result.