Question

I was recently looking at a config file that was saving some cryptic values. I happened to have the source available, so I took a look at what it was doing, and it was saving a bunch of different values and bit shifting them into each other. It mystified me why someone would do that. My question, then, is: is there an obvious advantage to storing numeric data in this way? I can see how it might make for a slightly smaller value to store, byte-wise, but it seems like a lot of work to save a couple of bytes of storage. It also seems like it would be significantly slower.

The other possibility that occurred to me is that is was used for obfuscation purposes. is this a common usage of bit shifting?

Answer 1

Bit shifting seems more common in systems-level languages like C, C++ and assembly, but I’ve seen it here and there in C# too. It’s not often used so much to save space, though, as it is for one (or both) of two typical reasons:

• You’re talking to an existing system (or using an established protocol, or generating a file in a known format) that requires stuff to be very precisely laid out; and/or
• The combination of bits comprise a value that is itself useful for testing.

Anyone who uses it in a high-level language solely to save space or obfuscate their code is almost always prematurely optimizing (and/or is an idiot). The space savings rarely justify the added complexity, and bit shifts really aren’t complex enough to stop someone determined to understand your code.