Creating an encrypted Time Machine disk on ExFAT

hdiutil create -stdinpass -encryption "AES-256" -size 500g -type SPARSEBUNDLE -fs "HFS+J" YourImage.sparsebundle

Where YourImage is the name you want to give your backup image and 500g is the maximum size of your disk image.

open YourImage.sparsebundle

diskutil list

Find your mounted image in the list and get it's path, in my case it was: /dev/disk3s2

sudo diskutil enableOwnership /dev/disk3s2

sudo tmutil setdestination /Volumes/YourImage

References:

• http://hints.macworld.com/article.php?story=20140415132734925
• http://garretthoneycutt.com/index.php/MacOSX#Creating_an_encrypted_sparsebundle
• https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man1/hdiutil.1.html