[Cryptography] Business opportunities in crypto

[Jerry Leichter]

>> Yes, your AP continues to broadcast an SSID - but if only your pre-authorized devices can effectively connect to it, why does that matter?
> 
> It matters if you care about privacy. Imagine the Wi-Fi network is in your car....
The message I was responding to specifically described a home network.  Revealing the SSID for a network that's in a fixed location reveals pretty much nothing - the location itself is already inherently an identifier that you can't avoid.

I agree with you that WiFi "talks too much."  The problem is that it's trying to solve too many problems at once.  In particular, it's trying to solve the "I want to be open for anyone try to connect to me at any time" problem - which means an AP has to broadcast its presence.  You could certainly design protocols to solve other problems.  One fully anonymous approach is for parties to pre-share a secret, and then one party or another (depending on what you want to accomplish) can send an encrypted "Alice is here, talk to me using key X" message where X is unique each time and the message is, of course, encrypted in a way that varies every bit in it with each X.  Only someone who can decrypt the Hello can tell who's there.

You could, I suppose, even build that kind of protocol on top of WiFi by using the SSID to carry the encrypted hello.  Very much like varying your broadcast MAC address each time - something you'll of course also need to do, but that's already done (with varying degrees of quality of implementation) to make clients untrackable.

                                                        -- Jerry