We survey the proposed software watermarking algorithms based on code re-ordering. This family of static watermarks use semantics-preserving transformations to encode a watermark in a permutation of the existing code. We describe the existing techniques and highlight the short-comings of these algorithms, namely that they are highly susceptible to semantics preserving transformations attacks.

Decompilation of Java bytecode is the act of transforming Java bytecode to Java source code. Although easier than that of decompilation of machine code, problems still arise in Java bytecode decompilation. These include type inference of local variables and exception-handling.

Since the last such evaluation (2003) several new commercial, free and open-source Java decompilers have appeared and some of the older ones have been updated.

Decompilation of Java bytecode is the act of transforming Java bytecode to Java source code. Although easier than that of decompilation of machine code, problems still arise in Java bytecode decompilation. These include type inference of local variables and exception-handling.

In this paper, we examine register allocation based software watermarking algorithms; these algorithms are constraint-based static software watermarking techniques. Figure 1 shows the evolution of this family of algorithms on which we report previous findings, describe some recent additions (including a correction to a published algorithm) and conclude by suggesting a direction for future work.

The rise in the use of the Internet and bytecode languages such as Java bytecode and Microsoft's Common Intermediate Language have made copying, decompiling and disassembling software easier. The global revenue loss due to software piracy was estimated to be more than $50 billion in 2008. Watermarking is a technique which attempts to protect software by inserting copyright notices or unique indentifiers into software to prove ownership.