I've always created and encrypted dmg's when I felt the need to. I was always wondering.... do I always need a Mac in order to open them? I know that there are other password protected file 'vaults' available out there. Are there any that may perhaps allow opening on both a windows or mac system? I also wondered about using 3rd party file encryption apps. What if some years down the road that app was no longer available or would no longer run on some newer OS. Or is one supposed keep re-encrypting stuff every few years in an never ending chore to keep your media current?