Java Is Based On The Research And Implementation Of Chaotic Opaque Predicate Code Obfuscation System

Software security has become one of the most crucial issues with the proliferation of Internet use.Traditional software protection technologies cannot protect software from malicious attackers well anymore,people have to develop new technologies to protect software copyrights.Java language is one of the mainstream programming languages which including complete' source code information in the compiled class file.It is easier to decompile and get the source code in reverse engineering.Therefore,Java language programs have become one of the hardest-hit areas cracked by decompilers.Code obfuscation is a special software protection technology,a large number of facts prove that it can play an effective role in software protection.Code obfuscation is mainly divided into data confusion?layout confusion and control process confusion.Data obfuscation and layout obfuscation techniques have been studied well.One of the research hotspots in code obfuscation area is to use opaque predicates to achieve control process obfuscation.The quality of opaque predicates directly affects the intensity of confusion.The traditional methods of constructing opaque predicates mainly employ simple mathematical formulas and basic number theory.These constructive methods are relatively simple and easy to be cracked.By combing the chaotic system with opaque predicates,this thesis proposes a method of constructing opaque predicates based on chaotic mapping.An improved control process squashing algorithm is also proposed.The contributions of this thesis are as follows:1.Analyzing and improving the confusion mapping function.Firstly,the problems of Logistic and En Logistic confusion mapping are analyzed;and then the Logistic chaotic map is improved.A Seg_Logistic chaotic mapping method is proposed,which overcomes the problems that the original Logistic confusion map gathers at the boundary and is insensitive to the initial value.2.Constructing chaotic opaque predicates.The thesis combines the improved Seg_Logistic chaotic map with Logistic chaotic map,proposes a method to construct opaque predicate,and gives an algorithm how to insert chaotic opaque predicates in the code to achieve the control flow obfuscation.The defects of the existing control process squashing algorithms are analyzed,and an improved control process squashing algorithm is proposed.3.System Development and Evaluation.A prototype of Java based on Chaotic Opaque Predicate Obfuscation Code System(COPCO System)is developed.The efficacy of the system is evaluated and analyzed further.