It should come as no surprise that we at Share One see system and network security as one of the main technical concerns for both our customers and ourselves. Consequently, the theme of this newsletter, and many of our future newsletters, will be built around secure technology and effective security practices. This month's subject is firewall technology.

What is a Firewall and Why Do I Need One?
An acquaintance of mine that works in the security business once explained to met that making your home or business impregnable was not really possible or desirable. The goal of a good security system was to make breaking into your home or business obviously more trouble than it was worth especially when compared to the buildings around yours. This concept can be applied to network security as well. The only way to make your system or network invulnerable is to sever all physical connection with the outside world. In this day of expanding web-based services and e-commerce this is not an acceptable solution. Using a layered security solution is considered by most to be the best approach. At the heart of this solution is the firewall.

There are many products on the market that are billed as firewalls but are, in fact, merely packet filters, which are easily defeated by a reasonably competent attacker. A true firewall incorporates several techniques to isolate your network from the outside world, creating an electronic De-Militarized Zone and allowing only the traffic that should legitimately have access to pass in or out. One of the most important techniques involves scanning the content of data packets for source, target, and other information in order to validate the packets against a set of rules defined by the network owner. Another technique uses Network Address Translation (NATing) to hide the internal network addresses from the outside world. The combination of these and other techniques makes it much harder for an outsider to "fish" for information that can be used to compromise a network.

As credit unions offer more web-based services and they themselves depend on information and services obtained via the Web, the need for permanent, high-speed connections to the Internet becomes more important. These services--such as cable, Digital Subscriber Line (DSL), and microwave communications--offer much better and more reliable performance and access than dial-up connections. Unfortunately, they also increase the credit union's exposure to attack. A correctly configured firewall should be a core of the credit union's defense. To be effective, the firewall configuration should be based on a thorough analysis fo the credit union's inbound and outbound network traffic. Merely installing a firewall "out of the box" will not provide the necessary protection. Share One will be glad to work with the credit union to help design the firewall configuration as part of an overall security plan.
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