Drive Backup requests access to read all files in your Google Drive. It does this so it can download any files you instruct it to, onto your local filesystem. In order to do this Drive Backup requests an OAuth token from Google, which if the user accepts, is the mechanism used to request specific files from Google Drive. This token is stored locally on the user’s device so they do not have to sign in each and every time a request is made.
Other than downloading files from Google Drive to store them on the user’s local filesystem and storing an OAuth token on the user’s device, no other data is requested, used, or stored on the user’s device or any other device on Drive Backup’s behalf.
No Google user data is shared, transferred, or disclosed with third-parties.
All data is encrypted while downloading and stored directly onto the local drive.