Hmm. Forgot to mention it my review, but there was actually some kind of a glitch when I tried to download SanDisk's latest version of the on-drive encryption software, so I just used the SanDisk encryption software that was already on the drive. And eventually I decided not to use it, because, ehh, I just thought it was a little clunky to use and there's gotta be better encryption software out there. But as to any other software requirements: Nope -- at least not for the Windows PC I use, and I doubt it'd be any different for a Mac. Just plugged it into the USB port & started using it.