Hi,

well there are some nice ideas for watermarks. If you are bored try analysing IDA itself. Its well know for its watermarks. However this sheme is build on the basis thats its compiled for each customer. So it depends on the number of customers. Some techniques used in IDA seems to be the order of the functions, or encrypting/decrypting a database with the key of the user. Using parts of the key to create a valid disassembling or it will just produce garbage. There are lots of ways to protect and watermark an application. It only depends on ideas in my opinion. If you create a tool only for a few customers and can compile the program for each customer you have a freedom to do nearly everything you want. The problem of watermarking a program which is designed for lots of customers is another topic. But here it only depends on time. You have the possiblity to compare different versions to find and remove the watermarks.