128 wep
wpa-psk
64 wep
wpa with radius server

which is more secure?

I have a router and 3 computers... one wired two wireless.. non of them are dedicated or on all the time...

(except the router obviously)

i don't know much about the 4th one.. but is it possible for me to use that one? or do i need a machine always on acting as .. well.. a radius server i guess..

WPA is more secure than WEP. WEP uses a static key for transitting. You can enter 4 keys in options but only one is being used while transitting data. WPA generates diferrent keys.

With 3 computers I don't think you need RADIUS. You need a RADIUS for more secuirty if you have a domain.

For using wpa your hardware must support it. If not you can use wep 40/64 or 128. With 128bit you have more secure than 40/64 but slower connections.

Choose one!!!

The performance hit for 128 Bit WEP (actually 104 Bit) is not statistically different than 64 bit (40 Bit encrpytion, 24 bit cypher) That is really a non issue but if all your hardware supports WPA then it's really a non issue because you wouldn't use WEP anyway. WEP is crackable in a few minutes with the right tools.

WPA, and specifically WPA2, is pretty strong encryption. Still vulnerable to a dictionary attack but just assign a long alphanumeric password (with a capital letter or two) and you'll be fine. Radius is overkill for a home network but if you wanted the strongest possible security on your WLAN nodes then RADIUS would further lock down the wireless network. You could also run a VPN to authenticate your wireless clients. That's what I do. IPCOP firewall with it's own network segment for the wireless clients and VPN authentication to allow traffic on that segment.

What??? 128bit is crackable in "a few minutes"? Can you provide link about that? (not how to do it, but that it is possible to do)

I thought that WEP and WPA uses very similar inscription algorithm, and the difference is only in the way how you generate the key. But if the key is of the same length, I thought that it is not easy to crack either of them.

Gotta find the toms article of defcon that had the FBI team on it. I recall they cracked a wep key using a couple laptops in under 5 minutes.

Sure

Google