All you need in order to do this is for the client to encrypt their password before sending it to the server. Often services that advertise “zero knowledge” platforms that use end-to-end encryption will authenticate their users in this way. If this were a website for example, there could be a javascript/wasm library used within the client page that encrypts their password before a login request is sent to the server.

See Freenet/Hyphanet

Please don’t, because it is literally the largest place online that openly trades CSAM. Law enforcement even run their own nodes there to try to catch people.

How long until this gets overrun with 🍕 and nobody wants to use it…

Not sure how moderation would even be possible with this model.