Comment by namibj

Proving to the tower that you are a paying user should be easy, but routing the data securely will not be as easy. You'd probably need some kind of onion routing or similar on the back haul, unless you want to forego incoming calls. I would not like to have to forego those. Also, why even bother with DHCP, just say that the tower assigns you an IP, without knowing your MAC, right after you were able to prove that you are a paying customer. Handling data quota is going to be non-trivial there, as you'd either need to route everything to the provider anyway, or have a DoS-proof way of decreasing your remaining quota, e.g. by signing a new value with some key of yours, ensuring that the tower can't use that as your ID (maybe don't tell him or so), and then have to prove to the tower that your quota really got diminished, preferably without revealing how much is remaining, and just telling the tower that you still got something to spare. The main issue seems to be that you'd have to hold a session with each tower where you got quote allocated, as you can't re-run that quote proof for each packet. The finest granularity that seems remotely reasonable would be like 16kiB of traffic, which you would deduct form your account, let it get claimed by the tower, and then be required to repeat for each successive block (obviously you could assign larger blocks, but a block, once assigned, can't be put back without serious unnecessary cryptographic hurdles.

I am not well-versed enough in these cryptographic details to tell you how one could do this exactly, but I doubt it's impossible/infeasible to create a cellular protocol technically as powerful as LTE, but without tracking ability by the tower or the provider (byzantine fault tolerance, stochastic).