This month’s Crypto-Gram is really good. Oh, wait, every month’s Crypto-Gram is really good. This month’s edition features articles on Microsoft’s Palladium technology, arming airline pilots, and the legislation that would have allowed media companies to attack computers suspected of trading in copyrighted files with impunity. Schneier’s explanation of why arming airline pilots creates more problems than it solves is typical of his exceptionally well reasoned approach to just about everything:

The real dangers, though, involve the complex systems that must be put in place before the first gun can ride along in the cockpit. There are major areas of risk.

One, we need a system for getting the gun on the airplane. How does the pilot get the gun? Does he carry it through the airport and onto the plane? Is it issued to him after he’s in the cockpit but before the plane takes off? Is it secured in the cockpit at all times, even when there is no one there? Any one of these solutions has its own set of security vulnerabilities. The last thing we want is for an attacker to exploit one of these systems in order to get himself a gun. Or maybe the last thing we want is a shootout in a crowded airport.

Second, we need a procedure for storing the gun on the airplane. Does the pilot carry it on his hip? Is it locked in a cabinet? If so, who has the key? Is there one gun, or do the pilot and co-pilot each have one? However the system works, it’s ripe for abuse. If the gun is always at the pilot’s hip, an attacker can take it away from him when he leaves the cockpit. (Don’t laugh; policemen get their guns taken away from them all the time, and they’re trained to prevent that.) If the guns remain in the cockpit when it is unoccupied, we have a whole new set of problems to worry about.

Third, we need a system of training pilots in gun handling and marksmanship. Guns require training to use well; how much training can we expect our pilots to have? This is different from training sky marshals. Security is the primary job of a sky marshal; they’re expected to learn how to use a gun. Flying planes is the primary job of a pilot.