FreeOTFE is quite useful when it comes to protecting the data from intruders and whether for PCs or/and PDAs. It is a freeware which offers “on-the -fly” disk encryption. It creates virtual disks on the system and these disks are encrypted.

These disks are encrypted and operate like a normal disk partition. Anything written on these disks is automatically encrypted and saved on your hard disk. You’ll need to create a master password with a key file. The most important feature is that the data encrypted on your PC can be read or/and written on your PDA, and vice versa.

You can create the encrypted volume using a very easy to use wizard. You can either encrypt a whole partition or use a file as an encrypted volume. And it supports Windows and Linux both. For Windows it runs from Windows 98/ME to Windows XP.

You can also use it on Windows Vista by disabling UAC. And it can run portablely from your USB stick or portable hard drive.