Elements of Defense

Purpose of a defense system

The Internet is a rough place, and it's getting rougher. What started as pranks, graffiti and vandalism has morphed into criminal activity -- some of it international in scope. You don't need a big hat and two six guns online, but you'd better know how to defend yourself.

The best defense in any context is always multi-layered. Think of it as a lock plus an intrusion alarm. The attack may get past one layer, but you hope the next one stops it. No defense is bullet-proof. The object is to reduce the risk to an acceptable level.

Backup is job one

If you have backed up the essentials, you can restore Windows, and get on with your life if all else fails, . You could even start over with a new computer. Backups protect against computer failure and your own foibles to boot. In a way, a firewall is more essential for online defense, but you don't do without the powerful last-ditch protection of systematic backup.

Perimeter defense

The best place to stop hackers and malicious computer code is before they enter. Your firewall is an essential first line of defense for your computer. I'd never go online -- even for a few seconds -- without one.

Firewalls will block ordinary hackers and Internet worms. A skilled and determined hacker can get past most firewalls, but it's not likely that you'll be the target of a sustained attack.

Email and Web pages go right through your firewall without even slowing down. They are allowed in because you expressly request them. As a result, your (informed) common sense is the only perimeter defense that you have against malicious email or Web sites. Firewalls can not protect naive users from themselves.

Internal Defense

Some hazards are going to slip through your firewall, and you're not going to catch all of the others. That's where internal defense comes in.

The gated perimeter at Happy Trails gives us a sense of security. You still need to be cautious. A few residents have learned that the hard way. You may want to keep your doors and shed locked at night to provide some internal defense.

Anti-virus and anti-malware programs can stop most attacks that get inside. But don't count on them - they aren't perfect. That's what makes peripheral defense so important. You need multiple layers, internal and external.

Configuring Windows, your browser, and your email client correctly, and keeping them patched provide the essential inner layer of a sound defense system. If they're strong and up to date they will brush off most of the threats that make it past the other defense layers.

Test your defenses

There are lots of free tests online that you can use these days. It's worse to have a defective defense than to have no defense at all. With your false sense of security you're bound to stumble into a trap.