Hello I just got cable internet and the cable company put in a wireless cable modem in my house. I do not have any wireless devices nor have any plans to have them.
My question is whether any one can break in to use my internet if I do not use the wireless functionality. (Apparently it must stay on with a wep key) They wouldn't let me turn the wireless off even though I am not going to use it!

I have heard to crack a network you need packets ie data transferred from the access point to a client to do this. Is it possible to crack if no one has the wep key and no one ever connects to this device.

I had a friend do a scan of my network and when he tries to connect to my ap (with a false wep key) it does send one or two packets of data.

So is it possible to crack this ap?

as i understand it nothign is impossible, but it's amazingly unlikely if you have a 128bit key on there. as you mention, you conventionally crack a wep key by sucking out of the air enough encrypted data to be able to guarentee that use can find a commonality in it and gain access. obviously a 64bit key works the same but is massively more susceptible. But without that data, they're onto a dictionary attack pretty much, and i really wouldn't worry about the changes of them managing that.

While several gigabytes of data is needed to crack WEP (regardless of key length, so don't feel that you are more secure by using a 128 bit WEP key), this is easily accomplished by generating WEP IV's using tools readily available on the web, most notably aireplay (http://aircrack-ng.org/doku.php). Using this technique it is possible to crack a WEP key in under ten minutes (and that's generous). If the cable company will not disable wireless access or turn on WPA2, there are very few options available to protect yourself from intrusion.

to my knowledge though aireplay can't really help because it needs an ARP packet. The correct ARP packet can only come from a client that successfully connects... taken from http://www.aircrack-ng.org/doku.php?...8b1428813f48d3

no one will be using this ap except for potential intruders.

quote:
unless the offender can think of a way to make the ap talk I dont think much but bruteforcing can help. Although as I mentioned earlier the ap does talk (send a few data packets with IVs) if someone is connecting to it with a false key..

Just as a suggestion, does your wireless cable modem have an option to limit access to specific the specific mac addresses of the computers connected via cable?

I'm sure if that would make the overall system more secure, but it may just add a minor extra bit of security.

Just as another suggestion: if push comes to shove, just wrap your modem/ap in tin foil . Seriously. Think about it.

Good idea a metalic net would do the trick... the broadcast wouldn't even get 10 feet away from it... sweet problem solved! ^_^
Thanks for your help!

Just for the same of discussion...

1) If you can adjust the router's settings, set a 128-bit key, or use a randomly-generated alphanumeric password. That'll help any brute-force attempts.

2) Disconnect the antenna.

3) As to the metal shield - it's going a bit overboard, and the wires in and out would defeat some of the usefulness, but you want a Faraday cage