Am I reading this right? You do still need internet access, to actually retrieve the page from someone else. Also I'm not sure how this will reduce data costs. Do providers charge different amounts for getting data from different servers? The same amount of data is still going into your device, it's just coming from somewhere else than usual

     In Public mode, Ceno will look into the BitTorrent network to see if another Ceno user has recently shared the requested page. If the service can identify the requested page, it will retrieve that page from another user's device. If the content is not available, Ceno will contact several Injectors to request that website and have it delivered to you.

     In Personal mode, you will only contact the Injectors to have that website fetched and delivered to you. The search will not connect to the BitTorrent network and will not attempt to locate the content on other users' devices.

    To ensure that your Ceno client can always contact an Injector, we have also created Bridges. If the Injectors are blocked on your network, the Ceno app will look for available Bridges, who will forward your request to the Injectors. The Ceno network currently features around 6,000 Bridges. Their number is always growing.

So on the one side it's some kind of shared cache of website resources, and on the other some kind of distributed tor-like edge network?

Quite clever! I wonder if it works well though, and if there is a risk of content injection by adversaries.

thinking out loud: it'd be great if web servers could sign their responses+timestamp, so you could guarantee getting the right content even through such intermediaries

How is Ceno making sure someone is not poisoning the cache?

edit: I try to read the paper and it's just referencing some RFC, which is not making me smart at all.

Again, how am I sure that when I am reading something from the cache, it's really serving what the site was serving somewhere else, and the person saving it there didn't modify it? Is it signed by the original page SSL cert?

edit2: ahh the "injector server", which is run by Ceno, retrieves the page and signs it. So you are moving the trust to Ceno and the central Ceno server actually does the browsing...? So the injectors can just see all the traffic? But that's inevitable I guess, someone needs to see the traffic