Encyption enabled but encryption option not selected

We have a clean install of 10.0.3.3 and have installed and activated the Default Encryption Module. Files are already being uploaded and it looks like they are being encrypted successfully. 'encryption:status' shows:

sudo -u www-data php occ encryption:status
  • enabled: true
  • defaultModule: OC_DEFAULT_MODULE

However, we have not selected an encryption option from the drop down on the Settings > Admin > Encryption page (see screen dump below). Does this default to Master Key? Should we select this option now or is it too late now that files are already being uploaded?
Many thanks,
Cliff

Can we use:
encryption:decrypt-all
To disable server-side encryption and decrypt all files as stated in the documentation?
Thanks.

This is how encryption works in ownCloud 10.0.3:

first you enable encryption: this enables the core subsystem for encryption, the plugin system
then you need to enable an encryption plugin/app because the subsystem doesn't do anything without it
you enable this app
then... this app asks you which mode you want to use
so before you selected a mode, in 10.0.3, no encryption is being applied
the encryption app only encrypts once a mode is selected
in 10.0.3

Now to your other question:

You can, but since you have not encrypted anything at this point, it would not do much I suppose.

Thanks Dmitry, that's really helpful.

No Problem, glad I could help you