Self-hosting encryption

I am completely new to Nextcloud and i love it.
Now I have a hosting package from GoDaddy.
With cPanel you can easily install Nextcloud with Installatron.
I’m running on version Nextcloud 20.0.7, PHP 7.3.23 and MySQL 5.6.49.
The files are encrypted with server-side-encryption and the server with full-disk-encryption.
The default encryption module app is enabled on version 2.8.1.
Are my files safe on a public ftp server from GoDaddy?
When I download the files from my ftp server I cannot open them.
I understand that, but the folders also contain the encryption key files.
Is there a possibility that my files can be decrypted?
I hope someone can explain this to me in a bit easier language.

The server-side encryption was designed for external storage (so not your Nextcloud server). Since all the decryption is done on your server, someone with full access to your server could get his hands on your unencrypted files.

If you don’t want to trust the provider, you should rather use client-side encryption. There is an implementation in the Nextcloud clients, not for that long (the desktop client is still improving), or you use a third-party software like https://cryptomator.org/.

Yes, you are right. The keys are secured by the user’s password. So “at rest”, they are pretty safe, but once the user logs in, someone could sniff the password…
There is another drawback of encryption, the files are also signed with information of the database, so it is extremely critical in backups, to store all data, keys and the current database state to fully restore the whole Nextcloud. I’d highly recommend to do a backup and try a restore as well!