Back in February 2007, I wrote that, “I’m more secure on a Mac than I was on Windows XP.” Much has changed since then—in particular, Vista and Leopard were released. Yet much hasn’t changed—I’m still more secure on a Mac. Again, I’ll explain my reasoning.

Again, however, I’ll caveat my statements by saying that I didn’t say that Leopard (that is, version 10.5 of Apple’s OS X) is more secure than Microsoft’s Vista. What I said was that I’m more secure on a Mac, and I truly believe it.

Before I go and re-visit the list of issues that I believe are at the heart of my rationale, let’s take a moment to explore some of the underlying major changes in the two systems versus their predecessors, Windows XP and OS X “Tiger.”

Probably the biggest single change in both systems is a fundamental shift in how they protect users and their data. Previously, the operating systems largely focused their security controls on the data/file entities—for example, a file might be readable to a group, but only read/writable to its owner. In Vista and Leopard, on the other hand, there are now security controls over user and application actions—for example, one application might be allowed to open an outbound network data session, while another is additionally allowed to accept inbound network data sessions.

What’s more, even though both operating systems have relatively rich sets of user account controls for permissions and such, these new controls on user actions happen largely at a user level. In fact, both operating systems seem to me to be moving away from the old school model of having an administrator account for system administrative purposes and user account(s) for day-to-day system usage.

Indeed, ordinary users can, in most cases, install software on the system once they have confirmed to the system that they want to and that they know the administrative password to do so.

This really is a fundamental shift in the usability of both operating systems, and I suspect they did it to make things easier and still (hopefully) adequately secure.

Perhaps it’s just me, but I’m not so convinced this is a step forward. Now, I’ll be the first to admit that the old admin/user model wasn’t functioning well in either operating system previously. But, I’m also convinced that the general end-users have demonstrated historically that they aren’t very good at making this type of security decision.

I’m reminded frequently of the old adage, “give a user the choice between security and dancing pigs, and they’ll go with dancing pigs every single time.” Obviously, this adage is tongue in cheek, but the point hits pretty close to home.

Giving the end users the equivalent of discretionary administrative control is a recipe that is more likely to fail than succeed.

With that out of the way, let’s revisit the list of issues from my XP vs. Tiger comparison.

• Familiarity with security mechanisms. Previously, I said, “One of the things that lured me over to OS X from Windows XP and Linux (but that’s another topic for discussion) is that under OS X’s pretty GUI lies BSD UNIX, for all intents and purposes. I’ve been using UNIX systems since the early 1980s and I’m very comfortable there, right down to understanding the underlying security mechanisms quite thoroughly.”

This statement remains true today in the Leopard vs. Vista realm, without a doubt.

The waters have gotten somewhat muddied, however, with the advent of the more user-oriented security model I describe above. The line between administrative and non-privileged has certainly blurred.

Qualitative score: OS X gets a B- while Windows gets a C-.