Question About Encrypting Time Machine Backups

[jason23432]

My laptop currently has file vault enabled...so my files are encrypted on my laptop.

I plan on using Time Machine to backup these files to an external hard drive...

Now here is my question:

Using disk utility I can encrypt the external hard drive before any files are put on it. I will probably do this so I can drag and drop individual files onto the external hard drive.

But, in addition to dragging and dropping certain files, I also want to use this external hard drive for time machine backups. So if I set the time machine to backup to this encrypted external hard drive...then will my time machine backup be encrypted?

However, this leads to my primary question. When setting up the time machine backup, Apple gives you the option to check a box that says "encrypt backups."

So if I select to "encrypt backups" in the time machine panel, even though I had already encrypted the entire external drive using disk utility, will the time machine backup be "doubly" encrypted?

If that's the case then I wouldn't check the box to encrypt the time machine backup, but rather just encrypt the entire external hard drive using disk utility.

Basically, what's the point of having the option to "encrypt backups" in the time machine panel of settings when you can just encrypt the external hard drive using disk utility and have time machine backup to that.

 

[KALLT]

The 'encrypt backups' option will make sure that the volume is encrypted before the backup is created. In other words, they do the exact same thing.

 

[Weaselboy]

Basically, what's the point of having the option to "encrypt backups" in the time machine panel of settings when you can just encrypt the external hard drive using disk utility and have time machine backup to that.

You get the same end result, but two methods of getting there.

If you format to encrypted in DU, then check that box, it will do nothing because the drive is already encrypted.

But if you do not format in DU, and just check the box, it does not reformat/erase the drive like DU did, but rather it converts the drive to an encrypted format, including encrypting any backups that may already be on there. If you have a lot of backup data on the drive, this conversion can take forever.