TrueCrypt can handle that, and is something you should at least have a play with in order that you understand it's ins and outs before attempting to support it yourself.
Incidentally, to comment for Gertrude the Wombat, i've just had a proposal to the NPIA for a secure system using TrueCrypt turned down for various very minor failings within TrueCrypt (not enough to trouble any but the most paranoid, but still a consideration for commercial secrecy). They recommend BeCrypt (which is a paid-for product) instead.
However, I would suggest TrueCrypt is good enough for all but the moon landing denialists.
