Encryption changes readable files into unreadable cipher
until the decryption key is supplied. With mobile computers outselling
desktops, it’s no surprise that encryption is becoming more popular than
ever. Keeping sensitive files encrypted
keeps your data secure even if your notebook should fall into the hands
of a stranger. Encrypting sensitive files also protects them from
spybots should the system become infested with malware. Luckily it’s
easier than ever to encrypt files and it's also free.
Encryption is built around complex algorithms that have been developed by various authors and go by names like Blowfish, Twofish, Serpent and Rijndael to name a scant few. These encryption programs use a single password
to encrypt and decrypt data, folders, and even entire disks. Other
types of encryption referred to as “public encryption,” use one key for
encryption and another for decryption, where only the latter key need be
private. This method is used to privatize email and instant messaging.
There
are many open-source, free encryption programs available that make it
truly easy to encrypt files. Most of these programs add a shortcut to
context menus. A context menu is the menu that pops up when you
right-click on a file. By placing a shortcut here, you can encrypt files
by simply right-clicking on the file and selecting the encryption
program. You'll be prompted for a password and the file will be
encrypted to this key. If this password is forgotten, the file will not
be able to be decrypted later
When you encrypt files, the last three letters of the file or the
extension will change according to the software. For example, when using
Pretty Good Privacy® (PGP)
to encrypt a Microsoft® Word® document, the file becomes
filename.doc.pgp. If you try to open the encrypted file by
double-clicking, you will be prompted for the password that was used to
encrypt it. If you encrypt files more than occasionally, you might
consider keeping all sensitive files in a single folder and encrypting
the folder instead.
Encryption options typically include the choice to automatically wipe
the original file after the encryption process has completed. A “wipe”
is a secure way to delete a file by rewriting over it many times so that
the data cannot be retrieved, even using recovery tools. Some programs
will allow you to dictate how many passes the software should make to
wipe the data. A minimum of eight passes is considered secure for most
purposes, while government or military might use up to 20 passes or
more.
Some encryption software
offers the option of adding an attribute to keep encrypted files from
displaying in Windows® Explorer®. It’s important to note, however, that
it’s a trivial matter to turn this feature off causing all files to
display, so this option should not be relied upon. As an alternative,
steganography encryption programs will encrypt files then hide them
inside graphic files that will still display properly. One such free
program is S-Tools®.
It is also possible to encrypt an entire drive or volume. For
example, you might keep all financial programs, banking, spreadsheets
and personal documents such as wills or other critical data on a
dedicated drive. By keeping that drive encrypted when it’s not in use,
you are protecting it against malicious software as well as prying eyes
should someone gain access to your system. It is also possible to
encrypt a drive that contains an operating system, though for most
purposes this is an overkill solution.
If you'd like to send an encrypted file to a friend as an email
attachment, you can use an encryption program to create a
self-decrypting file that will not require the receiver have encryption
software installed. A password will have to be supplied, however, either
by phone or some other means. Self-decrypting files are not considered
truly secure because the password must be conveyed to the recipient and
most passwords can be easily broken using software designed for this
purpose. Nevertheless, it's a good way to keep information private as it
traverses the Internet, as long as the information isn't too sensitive.
Open-source, free programs used to encrypt files, folders and drives
include TrueCrypt® and CompuSec® among others. If you would like to
encrypt email, look for a public encryption program. The Mozilla®
Thunderbird® email client can be used with the Enigma® plugin and GNU
Privacy Guard (GnuPG), an open-source version of PGP, to encrypt email
effortlessly and seamlessly. Correspondent(s) will also need a
compatible encryption program installed. There are also many other
alternatives available.
