Would any of you who run public HotSpots be interested in a way to authenticate users based on a special code that would be displayed on an LED sign?
For example, user gets on the HotSpot, tries to surf to a but gets a splash page (or captive portal page) that says please enter the code shown on the sign, user would have to be in the resturant or building in order to see the sign, upon entering the correct code (which is only shown for a minute or 30seconds?) user can then surf freely.
The code could be random and expires quickly, it might also ask for another part of the code shown on a sales reciept or food packaging (to verify they actually purchased something from your establishment)
In theory I would like to use already off-the-shelf hardware like the BetaBrite or Color Cells sign connected to the controlling PC via a serial cable.
I don't. The guy is sitting outside. He has to carry it in, type the code, then go back outside to enjoy the fresh air ? He can't just leave the laptop on the table and go check the number. Myself, I would go elsewhere. It's not going to stop the freeloaders. Whats to stop the guy from asking another person what the code is ? Sounds like a big pain in the rear.
I don't run any hot spots, but I do help maintain a few. One tried something like that. They would post a cardboard sign with the WEP key of the momement. It initially was changed every few hours, but that caused a big problem as it would disconnect users. So, it was changed to once per day. The local freeloaders would walk into the coffee shop, write down the WEP key, and then go to their car, camper, or van, and proceed to suck bytes. Some of the employees just gave out lists of the daily WEP keys to their "friends" for a small bribe. Not exactly what you're suggesting, but close.
I also know of one system (don't know name of vendor) that prints a number on the receipt that is used as a password. However, it apparently does not automatically expire and seems to function until the ARP table entry expires, or the router is rebooted. With some of the freeloaders, that can be literally forever.
That's built into NoCatAuth/NoCatSplash and its numerous mutations. The users get a splash screen. Type the magic password and they get to surf. It leaves a cookie on the users machine that is checked by the wireless router. If it expires, port 80 goes back to the splash screen and the user gets to re-enter the magic password.
It's an idea, but I'm not sure if it can be sold effectively. The basic requirement would be that it NOT involve any time or labor on the part of the coffee shop staff. If someone gets disconnected when the key gets changed, you've lost a customer. Therefore, your problem is not issuing the keys. It's dealing with key changes and expirations. Also return visitors that don't want the hassle. There's also the perspective of the owner. How much money will such as system generate or save? If near zero, then they won't buy.
Why he has a busy shop probably has more to do with everything BUT wireless access.
If you've got an idle link then freeloading won't be much of an issue. But what if you're in an area where nearby businesses deliberately leech your bandwidth and entirely clog the uplink? What good does 'free' do your customers when everyone else (who may or may not be a customer) hog it all?
It's all a matter of balance. Balance what you've got with what you're prepared to do to manage it, and what those efforts will 'cost' all-around. It does no good to 'manage' the connection if it aggravates your customers and consumes inordinate amounts of your staff's time. Likewise, it does no good to make it 'free' if people swamp the uplink.
Although, you can do things like change the antennas or limit the radio power as a means to keep the bandwidth consumable to within the premises. If it's free and doesn't work outside your establishment (as is necessary) that might save a lot of overhead efforts.