Doesn’t turning off SSID broadcast result in devices that have the wifi network saved repeatedly broadcast a request for the AP to identify itself in an effort to establish a connection?
They do that already... sum of all privacy losses.
Any time you go out in public your devices are crying out looking for your home AP. If someone can figure out which are you, e.g. by seeing you multiple times in different places they can then go look up where you live based on your home's SSID broadcasts.
Correcting myself: It appears that many modern client devices (at least current Networkmanager in linux, iphones, and grapheneos) have a "hidden" flag on saved SSIDs and only probe for hidden ones, so the ancestor post is correct for a least these devices.
Older and less sophicated clients, -- that don't explicitly have a 'hidden flag' for saved SSIDs will probe continually for all SSIDs they know.
I'm not sure I follow. Why would a network known to the device not be connected to the network? If you never connected your device to their wifi and only connected to your wifi connected via ethernet, why would it even know to make a request? If you're not actively connecting to the WiFi in your house, why not just "forget network"? Seems like a strange hypothetical, but aren't they all?
> Why would a network known to the device not be connected to the network?
I think they're referring to when you leave your home. Your device(s) will be constantly broadcasting probe requests for the hidden network.
The away-from-home probe requests wouldn't be that useful for mapping, but your AP/router is equally useful for mapping with or without broadcasting the SSID. Hiding your SSID just means it sets the SSID to null in the beacon frames but it's still sending out beacon frames with its far-more-unique MAC address (BSSID). If you're on linux you can see this pretty easily by running `sudo iw dev wlan0 scan`. The "hidden" wifi networks will have their SSID as "SSID: \x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" but all the other information including MAC address is still there. Personally it seems there are two "hidden" wifi networks within range of my bedroom.
