There’s an entertaining and illuminating post over at Ars Technica that gets into the nitty-gritty of exactly why wi-fi connections are so slow and generally… crappy.
I manage wi-fi networks in my own home and for clients. But I barely use them myself, and then only for my mobile devices, and only for basic functions. I’ve long since given up on the idea of using wi-fi for the bulk of my networking needs. All of my personal and professional experience has shown that wi-fi is only useful in terms of convenience.
The Ars Technica writer who penned the post, Jim Salter, apparently feels the same way. But he goes a lot further, with clear explanations for the problems you deal with when using wi-fi. And he has some good advice: don’t use wi-fi unless you have to; the more you use it, the worse it performs.
Public WiFi access points (APs) are extremely convenient. They’re also not very secure. Most WiFi APs are configured to use encryption, which is why you need a password to access them. Most also use strong encryption, in the form of WPA2. That sounds good, but if you’re at all concerned about security, it’s not enough.
Even with strong WiFi encryption, anyone who has the WiFi password and is within range of an AP is sharing the network with everyone else using that AP. That means they can use network sniffing tools to see all the traffic on that network. If you sign in to any web-based service (such as web mail, or your bank site), and that service doesn’t also provide encryption, your username and password can be obtained very easily.
Savvy public WiFi users know this, and use VPN (Virtual Private Network) software to further encrypt their network communications. VPN adds a layer of encryption that is dedicated to your computer and makes your communication indecipherable, even to the hacker at the next table.
Unfortunately, even with VPN software, your communications on a public WiFi network are vulnerable. That’s because – in a typical (i.e. default) setup – there’s a delay after you connect to the AP and before the VPN kicks in. During this delay, you are exposed.
To be truly secure, even with a VPN, you need to apply limitations on what your computer can do over public WiFi – especially what it can do during periods when the VPN is not yet active. Unfortunately, this can get complicated. The guides linked below should help.