One outstanding tool which you can use to encrypt the data on your devices is TrueCrypt. The good news is that besides being open source it also works on all major operating systems - Windows, Mac OS X and Linux. Rich with options, TrueCrypt supports a variety of encryption algorithms:
What makes TrueCrypt even more compelling is it's ability to create hidden volumes. Let's say for example that you are in a position where you have to give out the password for an encrypted volume. Countries like the US and England are now inspecting traveler's computers and refusal may give you quite a headache and possibly deny your entrance into the country. TrueCrypt can create a volume within another volume and since free space on any TrueCrypt volume is filled with random information when the volume is created, the hidden volume cannot be distinguished from random data even when the outer volume is mounted. Keep in mind that this feature is not available for Mac OS X at the moment but should be in an upcoming version.
What this article will show you now is how to create an encrypted volume that you can use to fill with data.
Before the wizard can begin creating your encrypted volume, it will instruct you to move your mouse as randomly as possible within its window. This enables TrueCrypt to construct encryption keys of adequate strength.
Once the wizard starts working, the amount of time it will take him to finish the job will depend mainly on the size of the encrypted volume you decided to create. The screenshot above says 2 hours because it was creating quite a large volume of 153 GB. The information window above shows TrueCrypt's progress at all times so you can plan to do other work until your volume is ready to go.
Once TrueCrypt is done and your volume is prepared you can opt to create another volume or exit the wizard.
In order to copy data into the volume you just created, you have to mount it in TrueCrypt's main window. You can mount more volumes at once and also check a box that will make sure history is never saved. Think about it, if you're already making sure your data is encrypted, you might as well cover all the tracks.
Every volume is protected by a password so make sure you use one that's strong enough and certainly not easy to guess. Your best shot is to usw a combination of uppercase and lowercase letters with numbers and a few special characters. Don't use anything from the dictionary and you're on the right track. There's really no point in encrypting data if the volume is going to be protected by a weak password.