And if you forgot the master password for accessing the encrypted volume ... then most of the time it can be almost impossible to access that data as well.
But again, depending on your need and the sensitivity of your data, encryption is pretty darn important nonetheless. In that sense, if you want an easy to use, one of the best data encrypting utilities available for your Ubuntu PC/Laptop... then the open source Truecrypt is one of the best!.
From installing in GNU/Linux to using its features... Truecrypt is truly :P an exceptional utility.
*. Encrypt partitions (including USB devices, etc).
*. Create encrypted volumes (portable).
*. Create "hidden" volumes within the encrypted volume/partition.
*. Supports few of one of the most powerful algorithms.
*. Encrypts and decrypts your data on-the-fly (oh yeah, it's fast!).
*. Add passwords to your volumes.
*. Dismount all volumes when logging out.
Truecrypt is a cross-platform app that can be run on MS Windows, GNU/Linux and Mac OSX... and you can easily create a portable version as well (more below)
1. You can install Truecrypt (7.0a version - which is the latest at this moment) in Ubuntu 11.04 Natty Narwhal, 10.10 or 10.04 by simply downloading the package from here first. And when downloading, make sure to choose "standard - 32 bit" or the "standard - 64 bit", not the "console only" package.
2. Then extract the content into your "Home" folder.
3. Open your Terminal and enter the below command (the name of the file will differer according to your version and 32/64 bit )
./truecrypt-7.0a-setup-x86or you can double click on the "truecrypt-7.0a-setup-x86" file (the file name, again will differ according to your version) and once asked choose "run in Terminal".
4. Then you should be prompted with a GUI wizard which is pretty easy to understand and simply follow your instructions on screen (as shown below screenshots).
|Step -1: Click on "Install TrueCrypt" ..., if you want make it portable, then choose the other option - "Extract .tar Package file".|
|Step 2: Click on "I accept and agree..." button.|
|Step 3: Click on the "OK" button.|
|Step 3: Now press the "Enter" key on your Keyboard to exit the wizard.|
Once installed you can access it via: "Accessories" -> "Truecrypt"
or just press "Alt" + "F2" and enter "truecrypt".
That's it!. Oh btw, you should be able to install Truecrypt in Fedora Core 15 or other versions (including most other GNU/Linux distributions) by using the same method. Good luck.