It is said that the United States traditionally prepares for the last war - meaning that the United States has historically been unprepared for the current war that it confronts. The last "great war" was World War II. Cryptography had everything to do with winning that war. Messages broadcast using early radio technology were out in the open for any covert ears to capture. Cryptography, however, turned public broadcasts into private communications. Conversely, cracking the code turned garbled nonsense into powerful information. In World War II, the allies ability to break the code was crucial.
In The Pond, the Germans communicated with their U Boat submarines during the Great Duck Hunt (the period where the U Boats roamed in wolf packs largely unchallenged, sinking ship after ship carrying supplies to the Britain from the United States) using an odd type writer like mechanism called The Enigma. Alan Turing leading the team at Bletchley Park developed one of the first electronic computing machines, cracked the Enigma Code, and turned the U Boat from the hunter to the hunted.
On the other side of the globe, US intelligence broke Japanese Code leading to multiple turning points in the War. Unsure of the destination of the massed Japanese fleet, the U.S. sent a low priority, unsecured transmission that Midway Island was facing a water shortage. When the Japanese sent a coded message that their target faced a water shortage, the Americans knew the Japanese battle plan and the famous Battle of the Midway was initiated. In another epic moment, the Americans intercepted a Japanese encoded message giving the specific flight itinerary of the famous Admiral Yamamoto. The United States sent a squadron to meet the notoriously punctual Japanese and deprived the Japanese Navy of the further service one of its great commanders.
It is in this context (and of course that of the Cold War) that the United States has become particularly anxious about cryptography. In the eyes of the United States government, cryptography is not just a cute mathematical algorithm produced by a bunch of software. Cryptography is a weapon. And you do not get to export weapons outside of the United States without the oversight and consent of an anxious government.
Of course this creates a bit of a problem. Cryptography is more than a weapon. It is also a vehicle for e-commerce. It is a vehicle for secure communications and transactions, including financial services and commercial transactions. Consumer faith in the ability to purchase widgets online will not be high where the cryptography used to protect the financial instruments, in other words the credit cards, can be easily broken by off the shelf code. For American companies to sell their software products and provide their services abroad, they need to be able to utilize strong encryption. But US export regulation, for a while, forbade it, and US products suffered a competitive disadvantage.
The debate of cryptography reached strange heights. Export of the cryptography violated US law. But discussion of the algorithm was arguably protected by the First Amendment. Thus, in order to get the code out of the country, instead of trying to move it as software, cryptography might print the code in a book and carry the book out. The government indicated that the code in the form of a book did not need an export license whereas the same code "in machine readable form" on a computer disc would. This ultimately led to T-Shirts with Phil Zimmerman's PGP code printed on them (including bar codes that made the shirts machine readable). The shirts were available to US citizens from a US address and the rest of the world from a UK address. The speaker proclaimed
Along with the sale pitch ("Now you, too, can become an international arms dealer for the price of a T-shirt") come warnings that if a non-U.S. citizen sees you wearing the shirt you may be classified as a criminal. (If you wear it inside-out, is it a concealed weapon?) If you are arrested, the promoters will refund the purchase price of the shirt.
Thus anxious US policy preparing for the last war confronted the reality of the competitive disadvantage this policy placed US companies and the fact that strong security was already largely available in the International community. After years of impasse, US export controls were relaxed in the waning days of the Clinton Administration.
- DOD National Security Agency "America's cryptologic organization. It coordinates, directs, and performs highly specialized activities to protect USG information systems and produce foreign signals intelligence information."
- See Junger v. Daley , 209 F.3d 481 (6th Cir. 2000) : Prof. Junger had sought to publish a cyrptography law text book which would indeed include samples of cryptography code. Prof. Junger asked the Department of Commerce if it might please clarify whether he needed export licenses for his book. Commerce concluded that the physical book caused no offense but if he desired to export the same in electronic form, this would require a license. Prof. Junger appealed the decision to federal court. The lower court concluded that there are not First Amendment protections for source code. The Court of Appeals disagreed, and returned the case to the lower court finding that Prof. Junger could make an argument that the restriction violated his Constitutional Rights.
- David Loundy, Is Your T-Shirt a Lethal Weapon? (May 1996).