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.

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