• Journal of the Korea Society of Computer and Information
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• v.18 no.10
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• pp.129-139
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• 2013

Java bytecodes are executed not on target machine but on the Java virtual machines. Since this bytecodes use a higher level representation than binary code, it is possible to decompile most bytecodes back to Java source. Obfuscation is the technique of obscuring code and it makes program difficult to understand. However, most of the obfuscation techniques make the code size and the performance of obfuscated program bigger and slower than original program. In this paper, we proposed an effective Java obfuscation techniques using assignment statements merging that make the source program difficult to understand. The basic approach is to merge assignments statements to append side effects of statement. An additional benefit is that the size of the bytecode is reduced.