How to encrypt a USB thumb drive on Mac OS High Sierra using Command Line

Chris Mendez -

How to encrypt a USB thumb drive with HSF+ (Journaled) using Disk Utility and Terminal.

WARNING

This article will teach you how to encrypt your drive as HFS+ (Journaled). Do not follow these steps if you want to encrypt using APFS.

Step 1 - Insert a USB drive and Open up Terminal

Step 2 - List Your Drives

Our first step is to list all of our available drives. Since we plan to format a USB drive, we will use grep as a filter and only show external drives.

diskutil list | grep 'external, physical'
Show all available external hard drives.

You should see something terrifying like this.

To find our USB thumb drive, let's look for clues.

  1. Clue 1 - external, physical means it's an external, physical drive.
  2. Clue 2 - Look for something that matches the name of your USB thumb drive. My drive is currently titled "STORE N GO."

Take node of the "IDENTIFIER." My identifier is titled disk2s1, and that is the drive and partition we will be formatting.

Step 3 - Reformat

This command is telling Apple's Disk Utility to erase the disk and format it for Mac OS Extended, Journaled Hierarchical File System Plus (JHFS+).

Take note that the only reason why this process works is that we are making a GUID partition map (GPT).

diskutil eraseDisk JHFS+ "My New Storage" GPT disk2
Erase the disk and format it for Mac OS Extended

Step 4 - Encrypt

This final step is to encrypt the file partition with the disk identifier disk2s2.

diskutil cs convert disk2s2 -passphrase
Encrypt the file partition

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