Feature: Full serverside encryption. Also of thumbnails

If you are on a shared Nextcloud instance and you don’t know if you can trust the administrators, you have two options:

  1. Don’t upload your personal/private files
  2. Or encrypt them externally with e.g. cryptmount (user-space, no sudo required) and external key on USB stick or any other similar program (e.g. VeraCrypt/TrueCrypt).

Then upload that encrypted container to the instance. Sure you want should keep it small so only put very critical files in it.