> > If so. Then why does your allow users to remove a removable key?
>
> I don't understand this, can you rephrase the question?
>
I have two separate drives: a boot device and a usb flash drive with a key. If I have a usb flash drive attached, grub should automatically unlock the main drive using such a key, if usb flash isn't here - grub should ask for a password for the main drive, not failing loading the whole system to the grub rescue.