OS X: How to Encrypt an External Drive

Below are instructions for encrypting an external drive in OS X 10.11 and above. Note that these steps will WIPE THE DRIVE so make sure there is no important data on your drive.

1. If your drive is new/blank start here (if not, skip to 2.):

Plug in your drive and when you see the prompt below click Initialize

Open Disk Utility (Applications/Utilities/Disk Utility)

Click on your external drive

If the Partition option is grayed out click Erase, if not skip down to 2.

Click Erase

Note: This will erase all the contents on your drive

When you see the Time Machine prompt click Don't Use

Back in Disk Utility click Done

2. If your drive is not new/the partition icon is NOT grayed out start here:

Make sure your external drive is highlighted on the left and click Partition

Note: If you followed the steps above and the Partition icon is still grayed out, just click on another drive then click back on your external drive

Click the Format dropdown and choose OS X Extended (Journaled, Encrypted)

Enter a Password twice and a Password Hint

Click Choose

If desired adjust the name of the drive in the Partition window

Click Apply

done

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