I have a dual-boot laptop with four partitions -
Ubuntu (OS) and
Ubuntu /home. I need to do full disk encryption on it. Ubuntu is running 12.04, Windows is Windows 7 Home Premium.
I don't see how to avoid to handle Windows and Ubuntu separately using software.
- TrueCrypt for Windows installation. For example this "How To Use TrueCrypt To Encrypt The Whole Windows System".
- Install Ubuntu using the alternate installer image. I recommend you to use LVM as it makes it possible to have all partitions (then LVs) in one dm-crypt container. It requires a
/bootpartition but LVM saves you from more. See this article how to do that: "How to install Ubuntu 11.04 on an encrypted LVM file system" (while a bit old, still relevant for 12.04).
Alternatively, get yourself an expensive Self Encrypting Hard Drive unlocked by your BIOS at boot time, if supported. This way, no configuration is required by your OS and all processing (encrypting/decrypting) is done by the hard drive instead of your CPU.