How safe is public wifi and how to make it safer?
Public WiFi hotspots are rarely “safe” at all, since the incorporation of security more or less defeats the “come as you are” nature of the things. They’re supposed to be easy access “on ramps” to the Information Superhighway, and so most public hotspots forgo any kind of ecrypted transmissions between the access point and the individual users, which in some schemes would require an encryption key be shared with users and changed frequently. Even those hotspots that do use WEP or WPA encryption schemes often don’t employ virtual LAN technology to create private subnets for each user. It’s fairly easy to “sniff” packet traffic even at many “pay for service” hotspots I’ve used, including some whose network operators you mention. If a Web site you communicate with properly uses SSL (Secure Socket Layer) over https protocol, at long key lengths, and you keep your sessions to reasonable lengths, you can be fairly confident that traffic between your browser and that Web server will remain pr
Don’t rely on firewalls to keep your files safe automatically, if you’ve enabled file sharing on your machine for home use. The wizard you use to do that will helpfully open holes in your firewall so that file and printer sharing actually, you know, works. When you connect wirelessly to a public hotspot, everybody else on the same hotspot is effectively on the same LAN as you. So, if you’ve got firewalling rules set up to only allow access to stuff from your own subnet, that means everybody in Starbucks has access. If you want to use a laptop securely at a public WiFi hotspot, you need to understand at least a little bit about networking, and you need to make sure your machine’s security features are configured appropriately. Don’t rely on Windows (or Zone Alarm or Norton or anything else) to look after you without you needing to jigger it, because it absolutely will not. At the very least, you should disable file and printer sharing before you take your laptop outside your home.
The first answer, by cactus, began with this: “Everyone on that same wifi network can see all of your traffic” That should read: “everyone who is trying to look” on that same wifi network. People will not casually come upon your traffic. They have to be looking for it. But of course it is smart to expect that they are out there.
