GnuPG and other PGP implementations allow you to encrypt (scramble the data so only intended recipients can read it) and/or sign (provide proof that the data has been unaltered in transit). As you should remember, PGP keys are made up of two parts, a public key and a private key. The public key can (and in most cases should) be available to anyone – there’s no harm in allowing it out to the entire world. The private key should be kept somewhere secure, protected with a strong passphrase.

Last time[1] we’d created our PGP key. Let’s jump in with some encryption and decryption examples.

Jumping right in, let’s create our PGP public/private key pair. I’ll use GnuPG, the Gnu Privacy Guard, available at http://www.gnupg.org, and which is very likely already available with your Linux distribution. If you want to use older free or commercial PGP versions, the commands are very similar. Any GUI front end will also have the same functionality.

File and mail security is easy to achieve with the right tools. PGP has proven itself the leader, and GnuPG is the tool of choice in the Linux world.

Network attacks are the biggest risk for Windows 2000 servers. Since the release of the old Windows NT 3.1, hackers have been actively looking for bugs in Microsoft Windows operating systems. Tools like SecHole, IISInjector, NAT (NetBIOS Auditing Tool), SMBRelay and L0pthcrack have been developed to reveal passwords, execute actions on a server, forge network connections and degrade system performance. In addition, several critical security vulnerabilities have been recently released for Windows 2000 that can completely expose a network to an intruder.

Wiretapping is a common occurrence; nothing is secure unless secured.

Where has your password been?