Is there a service for online editing of documents by several users with explicit encryption (end-to-end, zero encryption, local key)?

Question

Encryption

I can’t find a service for editing documents (docs + spreadsheets) by several users at the same time with explicit encryption on the side of each
. There are zoho, which promise super security, in principle, like Google, which had leaks.
There are different zoo of desktop applications for storing encrypted files with different encryption principles but do not allow online editing of documents by several users.
In AngloGoogle, I found several services that encrypt Google docs with local keys through the drive, but for some reason all these projects have been spun out, and there were even such ones in additions to Google Docs, and these extensions were also removed, which leads to suspicion.
Does anyone know of such a service?

Answer 1

I doubt very much the theoretical possibility of the existence of e2e encryption and collective editing.
Because the main logic for processing and merging actions goes on the server.
And if the server cannot see the content, then it cannot work with it in any way.
So all Google docs and similar services are automatically dropped.
And no one will hang it on the client, read how to give everyone the algorithms of work.
Only if the most basic public things.

Answer 2

https://cryptpad.fr
https://github.com/xwiki-labs/cryptpad