Encrypt files for privacy and security

Computers are often used to store private information that we wouldn't want others to see, such as bank and credit card information, company reports and documents, contact lists and so on.

It is worrying keeping so much important and sensitive information on our computers.

How can you keep all the files private and secure? If someone stole your PC or gained access to it either physically or through the internet, would they be able to access your files? How can you prevent this from happening?

You may want to consider encrypting them. There are several utilities that are able to do this and we will look at a couple here.

GCipher is a very simple utility that can encrypt files and text. In fact, they don't come much simpler and it is very old (v1.0 © 2003), but it is still useful. Look for it in your distro's package manager or software centre first, or go to the website if it's not there.

After downloading and installing it, it can be run from the menu. The graphical user interface version of GCipher doesn't appear to encrypt files. It has two sections and in the upper half of the window, labelled Decrypted, you can type in some text or copy some from elsewhere and paste it in.

Clicking Encrypt in the toolbar displayed the encrypted version in the lower half of the window. Encryption methods you can choose from include Gie's Code, Caesar;s Code, Rot and Vigenere.

The GUI version isn't very helpful, but open a Terminal window and run it from the command line and you can encrypt whole files. To encrypt a file using the Gie cipher you would type:

gcipher -c Gie inputfile outputfile

To decrypt the file you would change the -c to -C. It is straightforward, but what a poor choice of command line switch! You're sure to mix them up. Wouldn't it be better with -e to encrypt and -d to decrypt? Of course, this is Linux and the aim is to confuse and befuddle. It works and it's free though, so we shouldn't complain too much.

GNU Privacy Assistant looks like a much better utility. Get it from your distro's package manager or software centre, or try the website if you can't find it.

When it is first run you are prompted to enter your name and email address. These are then used to generate an encryption key. It does warn you that it takes a long time, but after waiting 10 minutes I gave up. I've seen good reports about it though, so you may have better luck (or more patience) than me.

GNU Privacy Assistant is a front end to GnuPG, which is often installed with Linux so you may already have it. It can be used from the command line in a similar way you GCipher (making that utility redundant). You can easily encrypt a file just by opening a Terminal window, changing to the folder containing the file and typing:

gpg -c filename

A new file is created with a .gpg extension and this is the encrypted version. You will need to delete the original file of course, (realy delete it - don't just move it to the wastebasket). To decrypt a file you just enter:

gpg filename1 flename2

Filename1 is the encrypted file and filename2 is the decrypted file. When you encrypt or decrypt a file you are prompted to enter a password. It's fast and if you are OK with typing in commands at the Terminal command prompt, it's easy. There are lots of command line switches and this is a powerful utility. If you are technically minded you might want to browse the full documentation.