How can I tell if my Time Machine backup is encrypted?

Is there a method to determine if a Time Machine backup disk is already encrypted?

Solution 1:

I thought I'll add to the subject since I was looking for this info recently.

It actually shows just above the progress bar if the backup is encrypted during the backup process.

I'm pretty sure this was there since Maverick.

Solution 2:

This is a little round-a-bout but, without dropping to Terminal or anything more technical, will let you determine the encrypted state of the volume.

1. Open System Preferences
2. Choose Time Machine
3. Click "Select Disk..."
4. Highlight the current disk listed under Backup Disks
5. Click "Remove Disk" button. This is NOT destructive. You are just un-associating the disk momentarily.
6. Click "Stop Using Disk"
7. Click "Select Backup Disk"
8. Select the same disk you just Removed ("Data" in my screen shot)
9. Select "Encrypt backups"
10. Click "Use Disk"
11. Authorize as prompted
12. If the disk is not encrypted you will see a dialog like the following
13. Choose "Use Unencrypted" to resume using the same volume unencrypted or "Erase Existing Backup" to create a fresh, encrypted backup.