Watermarking Java application programs using the WaterRpg dynamic model

We have recently presented an efficient codec system for encoding a watermark number w as a reducible permutation graph F [π*], through the use of self-inverting permutations π* and proposed a dynamic watermarking model, which we named WaterRpg, for embedding the watermark graph F [π*] into an application program P. In this paper, we implement our watermarking model WaterRpg in real application programs, taken from a game database, and evaluate its functionality under various watermarking issues supported by our WaterRpg model. More precisely, we selected a number of Java application programs and watermark them using two main approaches. First, we show in detail a straightforward or naive approach for watermarking a given program P which is based only on the well-defined call patterns of our model, and then we prove structural and programming properties of the call patterns based on which we can watermark the program P in a more stealthy way. The experimental results show the efficient functionality of all the programs P* watermarked under the naive-case and all the stealthy-cases. The size and the time overhead of the propose watermarking are very low.