Concern is rising about the amount of information that Google and other organisations are collecting about wireless local area networks (WLAN).
The latest news from experts brings little comfort: it’s impossible to make your own wireless network completely invisible to others.
All network-ready devices possess a unique identifier. “That’s the MAC address. And the WLAN router transmits it constantly,” explains Juergen Kuri from German computer magazine c’t .
The MAC address is necessary for network-capable devices to be able to communicate with each other at all.
Google claims that its search for WLAN networks has nothing to do with breaking into networks, Kuri says. It is instead intended as a way of establishing local maps of WLAN locations. A map of that kind could, for example, allow smartphone users to determine their location independently of GPS, and then use location-specific services.
“The WLAN doesn’t provide any location data of its own at all,” Kuri says. It is instead added by the organisation searching for WLAN.
The efforts have nevertheless drawn criticism from consumer advocates. Whether this cartography is harmless or not, WLAN operators should always keep their networks encrypted, Kuri emphasises, “preferably using the WPA2 standard.”
WLAN networks can also be made invisible to some extent. One easy way to discourage amateur hackers from trying to gain access is to prevent them from knowing the network is there at all.
Hiding the network means suppressing the display of the SSID (Service Set Identifier), a user-assigned label for the wireless network. It is normally visible to all WLAN-ready devices.
There’s no good reason to make the SSID visible to everyone. The owner knows the name and can enter it manually if additional computers need to join the network, Kuri says.
The visibility settings are handled in the router’s configuration menu. Those who do decide to leave their SSID visible should include a cryptic description and not their own name, Kuri recommends.
Otherwise, the pure WLAN location data suddenly gains a personal element.
