How to Encrypt a USB Drive in macOS Mojave

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How to Encrypt a USB Drive in macOS Mojave

One of the great macOS Mojave highlights is an encrypt-on-the-fly option, which is built into Finder. Finder inherits XTS-AES encryption from FileVault 2, which bans no-password access to data on a Mac’s startup disk. You can encrypt and afterwards decrypt any USB flash drive or USB-connected hard drive if you’re on the go and want to be sure your data is safe and secure on its way to another Mac. (Please note that this method only works with Mac; Windows desktops use third-party decrypting apps.)

Preparing a USB Drive

Starting with macOS High Sierra (10.13), Apple switched to the new HFS+ or Apple File System. Therefore, the encryption works with drives that feature GUID Partition Map only. Unfortunately, all USB drives from the shelf usually have Windows compatible FAT32 or NTFS systems and some bloatware from the maker. Our task is to get rid of both and reformat a drive.

Because data will be erased during the formatting, a very critical step is to pick up a used USB drive and copy the data on the USB drive to a safe location, like your Mac’s internal disk, iCloud, or any other cloud files storage.

It’s important to mention that the formatting process depends on your drive storage capacity and on the amount of data stored on it!

Here are all the steps you need to follow

How to prepare a USB Drive for encrypting in macOS Mojave.

Connect a USB drive to your Mac.
Go to Applications -> Utilities -> Disk Utility. Tip: Open Spotlight search and type in Disk Utility”.
In the Disk Utility toolbar, click the View button and select Show All Devices.
Select your USB drive in the left panel under the heading External. Tip: Click on the heading to see the drop-down list of all active external devices.
Click the Erase button on top of the right pane to bring up the Erase USB dialog. You have Name, Format, and Scheme
Type in the USB flash drive name. Try to choose the one you can easily recognize.
Click the Scheme drop-down menu and select GUID Partition Map.
Click the Format drop-down menu and select Mac OS Extended (Journaled). This enables you to open the encrypted drive on Macs with older macOS.
Click Erase. Wait for the process to complete. If it’s successful, the drive icon disappears and remounts. It’s normal; don’t panic.

Congratulations! You now have a blank USB drive! Close Disk Utility.

Encrypting a USB Drive

Attach the USB flash drive to your Mac and locate its disk icon on your desktop, in a Finder window, or in the Finder sidebar, then right-click (or Ctrl-click) it and select Encrypt “[USB stick name]”… from the contextual menu.

Open Finder and locate the USB drive icon in a Finder window, or in the Finder sidebar.
Right-click (or Ctrl-click) it and select Encrypt “[USB drive name]“… from the contextual menu.
Create a password as prompted by Finder. Tip: You can use our guide on Unique Passcode; it works for drives protection as well.
Verify the password and add a hint if you feel you’ll need it to remember the combination.
Click Encrypt Disk. Wait for the process to complete. If it’s successful, the drive icon disappears and remounts.

Congratulations! You now have an encrypted USB drive!

You can work with it in Finder like with a common USB drive: copy, open, delete files – they are encrypted on-the-fly! Of course, you have to type in your password every time you physically detach the drive or re-attach it to the Mac. So, if you forget the string of symbols, you’ll lose the access to the encrypted data forever, or have to pay for expensive forensics.

Usually, macOS prompts you to remember your password in Keychain. If you don’t trust your memory, check the box and the system will switch to automatic access by default. You can also decrypt the USB drive.

Decrypting a USB Drive

If you ever want to decrypt the USB flash drive in future, right-click (or Ctrl-click) its disk icon, select Decrypt “[USB stick name]” from the contextual menu, and enter the password to turn off encryption protection.

Plug in the encrypted USB drive.
Open Finder and locate the USB drive icon in a Finder window, or in the Finder sidebar.
Right-click (or Ctrl-click) it and select Decrypt “[USB drive name]“… from the contextual menu.
Enter the password to confirm the decryption.
Click Decrypt Disk.