I'm looking for a method of very simple encryption:
1) It must be able to encrypt a whole text file
2) The file must be decryptable using the same key
3) Security is not a big concern, mainly I just want the files to not be readable at first glance
3) I don't want to install any modules, .pm files, etc.
The reasoning behind this is that I have some files that I access with a script over the web, but the server they're stored on is a friend's, not mine. I don't want him reading the files, but he's not the kind who would spend a lot of time trying to crack codes, so something very simple would do. Any ideas?