In this chapter, we are going to explore the basic techniques and motivations for obfuscation of Linux programs. Techniques that obfuscate or encrypt binaries or make them difficult to tamper with are called software protection schemes. By "software protection," we mean binary protection or binary hardening techniques. Binary hardening is not exclusive to Linux; in fact, there are many more products for the Windows OS in this technology genre, and there are definitely more examples to choose from for discussion.
What many people fail to realize is that Linux has a market for this too, although it largely exists for anti-tamper products used by the government. There are also a number of ELF binary protectors that were released over the last decade in the hacker community, several of which paved the way for many of the technologies used today.
An entire book could be dedicated to the art of software protection, and as the author of some of the more recent binary...