Fixed size encoding scheme for software watermarking

Abstract

Software piracy has become a major threat to software developer. One of the techniques that can be used to discourage piracy is watermarking, by embedding developer's watermark into software which can later be extracted to prove ownership. During the last few years, different algorithms were developed to embed watermark inside the software. One of the algorithms is dummy method insertion technique whereby a dummy method that embeds watermark is inserted in software application. However, the disadvantage of this algorithm is that the watermark is embedded in a particular instruction in the dummy method. Due to that the length of the instruction is dependent on the length of the watermark. Thus, this situation put dummy method in suspicions and become noticeable to the pirates. In this paper, we present an encoding scheme that could produce fixed size encoded watermark and thus making the encoded watermark in the dummy method less noticeable. The proposed encoding scheme uses a hash function so that encoded watermark is always fixed even though the size of watermark character varies. As a result, our encoding scheme produced fixed size dummy method and could make the dummy method less noticeable to the pirates.