Wireless data communications has become a tremendous success. The protocol used by most wireless computers is the 802.11 standard. But how secure is wireless data communications? Here is a short overview covering the basics about wireless security.
The 802.11 protocol from IEEE (Institute of Electrical and Electronics Engineers) defines a number of standards for link-layer protocols. The most popular of the 802.11 standards are the 802.11b and 802.11g. If your computer is using WiFi, you are most likely to use the 802.11 protocol.
Wireless data communications creates additional security issues. If your computer is connected to the network with a cable, someone who wants to eavesdrop on the traffic would have to get access to the cable and find a way of undetected eavesdropping on the traffic. It is not impossible but requires a lot of resources and technical skills. Wireless networks on the other hand, have no such security. The packets are broadcasted and can be received by anyone in the neighborhood. Of course, the individual packets have to be interpreted and put together in the right order. Not easy to do but you can download programs that do such things for you from the Internet.
So how can you protect yourself in a wireless world? Fortunately, the 802.11 include some security features, helping you to protect yourself. All wireless traffic can be encrypted. This is very important, since the data is broadcasted and can be received by anyone within the broadcast range. It is not even necessary to be logged onto the specific WiFi network. Thus, always encrypt the wireless traffic, otherwise you have no security what so ever.
Note that many WiFi hotspots don’t use encryption. You may want to be very careful in such places. Don’t log on to any sites that don’t use SSL, which will give reasonable protection. For sites using SSL, make sure to check that the certificate is valid. If the certificate is not valid, it could be a Man-in-the-middle attack. An SSL connection is encrypted by the end-devices and can not easily be decrypted by outsiders.
If you connect to a VPN, using unencrypted wireless networks is not a big security issue. The VPN software will encrypt the traffic. Note that today it is even possible to eavesdrop on unencrypted wireless traffic using just a smartphone, no computer is needed.
The two main encryption standards are WEP, Wired Equivalency Protocol, and WPA, Wi-Fi Protected Access. WEP is an old protocol and not very secure with today’s standards. Although very few people are capable of personally cracking WEP, it is possible to download programs that will do it for you. WPA is much more secure but also it has a couple of shortcomings.
The basic version of WPA encryption makes it possible for anyone who is logged onto the WiFi network to read the traffic of others logged on to the same network. And finding out the password of the network is seldom very difficult for someone who knows what he is doing. The more secure versions of WPA require an authentication server. It is a very sound investment for companies but not for home networks.
Note that the feature of not broadcasting the SSID does not significantly increase the security of your WiFi network. It is easy to discover the SSID even if it is not broadcasted. You can find plenty of tools on the Internet which discover the SSIDs of all WiFi networks in the neighborhood, regardless if the SSID is hidden or not. Additionally, hiding the SSID may cause problems for legitimate users.
All in all, WiFi has a number of security issues but as long as you are aware of the problems you can use WiFi without worrying too much about the security issues. Just make sure that you are using strong encryption, for example SSL or VPN, when you are accessing sensitive data.