So this site covers some of the basics about linux crypto (including the crypt a file and how to make encrypted partitions). How is this important? Well lets just say that just because you have nothing to hide doesn't mean that you have to publish that fact. Crypto is good for you and good for your mental privacy. Remember if someone finds your new patentable idea and you can't prove that you were the first one that thought it, it's going to cost you money. And it will cost more money anyway with the court battles.