Two Obfuscation Methods by Controlling Calculation Amounts and by Table Function for Watermarks

This paper describes new two obfuscation methods the fist method can control computational complexity and the second method can achieve semantic obfuscation. The computational complexity can be strictly controlled by using the technique of RSA encryption. The computational complexity can be arbitrarily specified by the impossibility of factorization of prime number in RSA encryption method. Semantic obfuscation is achieved by transforming a function into a table function. The table function method only shows input data and output data .It hides all the intermediate processing data . Because the explicit function form is hidden, it is thought that analysis takes time. The computational complexity technique and semantic technique can be used at the same time, by embedding the table function into the program with computational complexity method.