6.1. Introduction
Code Virtualization​
Many of us consider particular pieces of code especially important. May it be a license code check algorithm implementation, an innovative optimization method, or anything else equally important so we would want to protect it by any means possible. As we know, the traditional obfuscation techniques basically do renaming of symbols and encryption, thus leaving the actual algorithms — cycles, conditional branches and arithmetics potentially naked to eye of the skilled intruder.
Here a radical approach may be useful: to remove all the .NET bytecode instructions from an assembly, and replace it with something completely different and unknown to an external observer, but functionally equivalent to the original algorithm during run time — this is what the code virtualization actually is.
Eazfuscator.NET provides an implementation of custom virtual machine which works atop the .NET virtual machine, using a different virtual instruction set every time you obfuscate your application. This makes the code of a protected algorithm completely bullet-proof and hidden from others. All you need to hide your precious logic is to apply a special attribute to your methods or classes.
Data Virtualization​
Not only the code but data can be virtualized too. The virtualization changes the way the data are represented in memory and on disk. The resulting data representation is something completely different and unknown to an external observer, but functionally equivalent to the original algorithm during run time.
Code and data always come together, so it is beneficial to use both kinds of virtualization to achieve better protection results.