The encryption process depends on how much data you have on the USB flash drive, but you'll know it's completed when its disk icon disappears and re-mounts. (Don't forget this, otherwise you'll lose access to any data stored on the USB drive!) Once you've chosen a password, verify it, add a meaningful hint if desired, and click Encrypt Disk. When you select Encrypt, Finder will prompt you to create a password, which you'll need to enter the next time you attach the USB flash drive to a Mac. To resolve this, you'll need to erase and encrypt the USB drive in Disk Utility – before that though, copy any data on the drive to another location for temporary safekeeping.) (Note that if you don't see the Encrypt option in the dropdown menu, your USB flash drive hasn't been formatted with a GUID partition map. With that in mind, here's how to securely encrypt your USB flash drive.Īttach 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 ''.

If this is a requirement, you'll need to use a third-party encryption solution like VeraCrypt. Note that the following method is only compatible with Macs – you won't be able to access data on the encrypted drive using a Windows machine. Using this convenient Finder option, we're going to show you how to encrypt a USB flash drive (or 'thumb drive'), which is useful if you're traveling light and want to take sensitive data with you for use on another Mac.įinder uses XTS-AES encryption, the same encryption that FileVault 2 uses to prevent access to data on a Mac's startup disk without a password.

In macOS Mojave, you can choose to encrypt and decrypt disks on the fly right from the desktop.

Password protect external drive