This post is the first in a series dedicated to disk encryption in Linux-based operating systems, namely Debian GNU/Linux 3.1 (sarge), but all these tips should be useful for other systems too.

As portable mass storage devices (such as USB flash drives, external hard disks or even laptops) are becoming more and more popular there’s a growing need to keep all this data secure in case a device is stolen (of course to keep your files secure you should also back up them, but that’s a different subject I will not cover here).

Disk encryption is a complex issue: there are plenty of encryption algorithms and disk format standards. New systems appear each year and old ones become deprecated. All these systems vary in speed, complexity, security and even stability. To put things worse, most disk encryption systems are not compatible to each other and are usually limited to one specific operating system.

There’s a wikipedia article about disk encryption software that can serve as a quick overview of some of the most popular systems available.

In this series of posts I’ll write about some of the most basic forms of encryption to cover the usual needs. I’d like to note that I’m not writing about user programs that encrypt files manually, such as GnuPG or some ZIP compressors. I’ll just cover methods that encrypt filesystems on the fly, that is, once set up you don’t need to care when you change your data: it will be encrypted automatically as you write it to disk.

I hope you’ll find these articles useful. Comments and criticism are welcome.