Mac+PC networking security

Clarifications

WPA at a minimum on the router. Use the Windows firewall at a minimum or something like Zone Alarm. Depending on the Mac, there is a firewall utility or a free .dmg called "Flying Buttress". Use an AV- for Windows consider AVG from grisoft.com. For Mac, I think that Clam is available.

Because of the differences in the two operating systems, you will need to use different tools on the machine itself. But that WPA at your wireless router is the best thing you can do for starters and protects both machines.

Good luck!

If it is just locking down your WiFi Access Port then Tig's suggestion is quite good.

But if you mean Securing the Actual Traffic across the WiFi Network that is much harder to do.

About the only way that you can do this is to remove all possibility of someone outside being able to access the actual Wireless Traffic. This involves constructing a Faraday Cage around the environment that you use the WiFi in so as to prevent any Radio Signals escaping the building/Room or whatever.

Or the best way is disable the WiFi and run CAT5E Cables directly to both computers. It's much cheaper and far faster than anything else that is available to you. It will also give you the benefit of a Faster LAN as well because the Radio Link is slower than a Wired link.

OH I nearly forgot update the Firmware on the Router as well and do it every time that a New Firmware version becomes available.

Col