I have recently decided to sell my Android device (MotoG3). I know that before I sell it I am supposed to Encrypt the device before I perform a factory reset as it is my understanding that the Encryption keys will also be deleted, therefore making any recoverable data unreadable.
However I am confused as to whether this also applies to data previously stored on the device BEFORE the device was Encrypted.
E.g. I have had many photos (and other files) on my device in the past which I have decided to delete to free up space, however at the time of deletion my device was NOT Encrypted.
So what happens to these files after I Encrypt my device and perform a factory reset, are they recoverable or is the hidden space which the files previously occupied also encrypted?