What is WiFi?
WiFi is a technology that is widely in use today, It uses high frequency signals to send data between computers and allow wireless internet access. Most people use WiFi everyday without thinking about the security implications of sending sensitive information over radio waves.
Tip: Anything that's being transmitted can be intercepted!
Types of wireless security:
First I will start with NO security, There are still a lot of people out there who use whats called an Open network. This means there is absolutely no encryption and anyone can connect to the network. This is very dangerous!
The next type that is most common is WEP. There are a lot of problems with this standard and it's incredibly easy to crack the encryption and connect. If you use WEP, You should think about switching to the next type of security im going to talk about!
This is by far the best method of securing your network. Crackers will need a vast collection of word lists to get the pre shared key. While it is the most secure method you can use today, You should try to use a complex password that's not found in the dictionary. I recommend a password of at least 20 alphanumeric characters.
So what are the dangers of using weak encryption?
If you are using an open connection the dangers are immense! All a Cracker would need to do is connect to your network and start sniffing the data. This means all of your passwords for Facebook, Your bank and everything else can be compromised without any effort whatsoever!
As for WEP, This can be easily broken with tools downloaded from the internet. Specifically Backtrack Linux, It has everything anyone could ever need. The Cracker could fire up a tool such as Gerix and in a matter of seconds have your wireless password. The rest is already detailed above.
WPA/WPA2 is your best bet, If you have a good password it will be very hard to get into the network from a wireless connection. I recommend AES encryption for use with WPA.
Tip: Make sure WPS is disabled in your router settings. If this feature is enabled, It doesn't really matter what type of security measures you use. A tool like Reaver or Cowpatty can exploit this feature and get the password.
Please educate all of your friends who use WiFi about these risks and help them to secure their network.