External Hard Drive Encryption

Solution 1:

Apple encrypts disks with APFS currently and before that using Core Storage. You can get security information from the security white paper:

• https://support.apple.com/guide/security/welcome/web

I believe macOS uses 256 key length across the board, but can’t find that from the command line yet.

• https://support.apple.com/guide/security/data-protection-overview-secf6276da8a/web

Open the terminal if you prefer command line solutions - these two commands will dump all encrypted volumes:

diskutil apfs list
diskutil cs list

If you prefer a graphical tool, you can open the Disk Utility (use spotlight or open the Utilities folder within the Applications folder) to inspect each drive as you connect them.

• https://support.apple.com/guide/disk-utility/encrypt-protect-a-storage-device-password-dskutl35612/mac