I've heard there are Wifi sniffer programs that can be downloaded to be able to eavesdrop on what nearby people are doing with their computers in a public Wifi setting, but I was wondering if there is anything available that could act as a countermeasure for these programs, and thus keep someone safer while using a public Wifi internet connection. Does anyone know?

Make your wifi private with a password.

Oops! I'm sorry I didn't make myself clear about what I meant. I meant when using public wifi, such as a local library, how do I keep others from using sniffer programs to see what I'm doing, see my passwords, etc.

I'm familiar with using passwords on a home wifi network. The librarians have told me that the wifi at the library doesn't require any passwords, so it's an open network.

You could ask them if any information from the wifi network is public...im not sure

There is a program you can get that creates some sort of VPN tunnel between you and the router,i will post back if i fnd it

Thanks Mr. N!

I didn’t know what VPN meant, so I looked it up. It means virtual private network, correct? Is this something easy to set up? My goal is to use a laptop computer at the public library using their public Wifi service. How do I use a VPN to make sure nobody is able to intercept and monitor my activities? Is VPN a program that can be installed on my computer? I guess I just don’t understand exactly what it is.

Here is my awsome VPN diargram!

I got VERY bored and decided to draw this(It looks awsome dont it!)

IVE FOUND THE SOFTWARE@
http://www.hotspotshield.com/
Seems easy to set up and is free!(No nag screens)

This post has been edited by Mr.N: Dec 28 2009, 03:34 AM

That looks just like what I need! Thank you!
Also, that really IS a good drawing!

Make Your password private

Older wifi routers use what's called "WEP" authentication. This is a weak system and can be brute force cracked.

New wifi routers use what's called "WPA." This system doesn't have an "easy" way to crack through.

So, switch your system over to "WPA." You'll be more secure.

Also,

Don't have your router broadcast your network name/identity. Make people who want to use your system ask for the name.

OR

Only allow certain MAC addresses onto your system.

Sage words from jStrickland alas this is just the tip of a very ugly iceberg that is cause for concern with all WiFi Connections, be they WEP, WPA or VPN protected.

Cryptology is an ever advancing field and though there are measures the average user can take to defend thier router the fact of the matter is that a typical WEP encrypted WiFi network can 'cracked' in under twenty minutes. The 'brute force' method is not employed as there are far more elegant ways to find the key... and NO I'm not going to tell you how.

Switching of the AP name broadcast and invoking MAC filtering so that only your equipment knows the router is there and has access is a good start but..

IT WILL NOT STOP A HACKER..

Changing the encryption system to the WPA/PSK option (if available ) on the router will however seriously slow a would be WiFi hijacker down. Again they do not need to rely upon a brute force (trying billions of combinations) to find your access key. However the process is more complicated and would at least deter the less competant WiFi hijacker.

Do change your home or business WiFi router access code regulary at least once a week and turn off the WiFi at night if posibble. Do use a randomly generated access code as this prevents 'Dictionary' based attack and the simple technique of just guessing the password.

This topic is really old and he already said he used my solution so im closing it.