In the Crypto Wars, arguments have occasionally been made that there is a constitutional right to cryptography. Most recently, Apple made that argument in trying to fend off the FBI’s request to help break into an encrypted phone. It went roughly as follows: writing code is an expressive act, freedom of expression is protected by the First Amendment, and so they can’t be forced to express themselves in ways they don’t want.

I don’t think this argument would have fared well in the courts. Corporations (and individuals) are regularly forced to express themselves in ways they don’t want. Enviromental regulations force them to write MSDSs (among many other things). Tax regulations force them to fill out tax forms, and the ways they do so can be, uh, highly creative. Being forced to express themselves in such ways doesn’t prevent them from making whatever arguments they want in public.

But there is an amendment in the Bill of Rights that really is a good match: the Second. The Second Amendment is about private possession of weapons of war; crypto has eminently been a weapon of war. It is about preserving the ability to resist tyranny; and if the government were to have the power to snoop on every communication in a modern computerized society, it would enable a level of tyranny so oppressive as to make every tyranny in history seem mild in comparison. It is also about self-defense against criminals; and there too the fit is good – not just because cryptography is essential for protecting such things as online banking transactions (though it is); it also ties in to personal self-defense, as might be performed with a firearm. To assassinate someone, a key piece of information is where they will be in the future; a good defense against assassination is to vary one’s schedule in an unpredictable manner. If you can read a person’s communications, you can predict where they will be; and if you can predict where they will be, you can put a bomb there or send a gunman there. If they will be wearing a bulletproof vest or bringing a bodyguard, you can get that piece of information too from their communications, and choose your weapons so as to pierce that vest and your team so as to outnumber any bodyguards.

To return to Apple’s argument, firearms design can be quite an expressive act too. The designs of John Moses Browning are said to have a distinctive character, and are revered by many; one of his designs, the M2 heavy machine gun, recently completed its hundredth year in active duty with the US Army. But people would think a gunsmith was out of his mind if he proclaimed that he had a First Amendment right to make whatever firearm he wanted, and would tell him: no, whatever rights you do or don’t have in that regard come from the next Amendment in the list.

To say that the Second Amendment covers crypto is admittedly a completely novel interpretation of it; but much is said about the need to interpret the Constitution in accordance with the needs of modern society, and this is a lot more natural than many of the reinterpretations that have been foisted on us under that argument. Technological change means that cryptography isn’t, as it was in the era of the Founding Fathers, just something done by hand; now it’s weaponized, so weapons freedoms apply. The First Amendment protects discussions of weapons; the Second Amendment protects actually fielding them.

This is not to imply that all the present rules for firearms would apply without change to crypto, or that they’re even really the right rules for firearms. It’s too easy to use crypto without knowing it, and too much of modern society depends on doing so, for there to be much sense in, say, prohibiting it for convicted felons. It’s also a lot easier to download a program than to make or buy a firearm, which weighs strongly in favor of having the laws looser: a law that’s too easy to flout is best not made at all. Also, there are many sillinesses in weapons law, and it would not do to duplicate all those for crypto. But making use of the Second Amendment would still be better than not making use of it.