How to demonstrate disk encryption?

Question

I'm having security classes and in one of the works I need to create a fictitious Company and demonstrate one security tool/improvement.

I've chose to encrypt one Windows VM with TrueCrypt (AES) and show that is encrypted... I have two Windows Virtual Machines. (And Kali, Mint, Fedora ISOs to boot from...)

TL;DR; How can I show that I can't access the data on a disk encrypted by TrueCrypt?

1. The encrypted partition does not automatically mount when on linux live cds... (This is one way to show it, but it does not prove it, because it could be a disk problem...)
2. Besides "cat /dev/sda1" showing random junk... (and showing some strings on the "normal" vm...)

Answer 1

I think your best bet would be to use an algorithm to test for randomness such as "DieHarder". It would suggest, but not prove, that the data is pseudo-random.