We use the aes library by Dr Gladman, which is also used in WinZip. It can be used for other encryption support as well, and also provides a PRNG, SHA, and other things.
git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@2955 dfc29bdd-3216-0410-991c-e03cc46cb475