Network Computer Security.

I noticed an open wireless connection at my doctor’s office on my last visit. I gladly used the access to the Internet while I had to wait (he was unusually late). After a while, I decided to check out who was offering this free connection. It turned out to be my doctor. When I told him about my discovery he was very surprised. He had paid a “professional” service to install it for him. When I gave him a floppy with a copy of some of his data off his server he was even more surprised.

Computer networking is so easy and so prevalent that most people do not even think about how to do it or possible security concerns. Most people, most of the time operate in a “trusted” network where you are probably safe. However, some situations require special attention or your private data may be accessed by strangers. Someone wanting to harm your system can do it with very little effort and no special tools or software hacking programs. You must be aware of these issues and set up your computer accordingly.

Wireless routers for home-office or work are very popular but can expose you to serious problems. Traveling around town using various hot spots introduces a different set of possible problems. Computer networking is powerful and simple to set up. However, if not done correctly you could be exposed to serious security problems.

Prevent unauthorized computers from gaining access to your local network.

The biggest risk is an open wireless router. Out of the box they invite everyone to join. You must perform the simple task of securing your wireless network or you should expect anyone within a few hundred feet to use your network. Some people think the only thing at risk is sharing the Internet (no big deal). But file sharing is a primary reason for creating a network and anyone on the inside of a network has as much access to your data as you do.

There are various levels of security you can add to your wireless router. The manual that came with the router can explain each step in detail. Use encryption at a minimum. Use WPA if that is an option. WPA is more secure than WEP but the router and all computers needing access to the network must support it. For most people WPA security is all you need. If you would like more security, use the MAC validation capability of most routers: it only allows predefined computers to join the network. While you are at it, change the master password to the router just in case someone gets their hands on one of your computers so they won’t be able to reconfigure your wireless.

If you use your computer at a hotel or public hot spot all the people around you can see your computer.

Always run a firewall whenever you are directly connected to a public network. This includes dial-up connections. XP has a built-in firewall that can be activated but the default settings allow file sharing and sometimes other types of remote access. Make sure you check the box that indicates you do not want to allow any exceptions.

Zone Alarm offers a free firewall that can be downloaded from their web site. Zone Alarm works well but is more complicated to set-up and use than the XP firewall. Turning on a firewall stops all access to your computer from other computers, including those you may want to give access. A properly configured firewall can protect you from the Internet and still allow local desired access. If you want to try ZoneAlarm you can find the link under downloads on my web site: www.michaeldion.com.

Beyond having your shared files exposed to everyone, some applications like email send your user id and passwords as clear text so anyone with a network analyzer can record all your key strokes. Using the web email application solves this problem assuming yours runs a secure web site (look for the little yellow lock at the bottom of the web browser). In general, assume anything you do on your computer at public site is being monitored by someone unless you are connected to a secure web site or running a VPN client (a complicated topic for another newsletter).