Cryptic clues


This comes from a poem by Sharon Hopkins: @dawn, dance; @evening, sing; read (books,poems,stories) until peaceful; study if able;

What makes it remarkable is that a computer can understand it too, since it is written in Perl, a computer language so perverse you can write English with it. So if you type in the whole poem as a Perl program, the machine won't crash. It won't do anything useful either, but that's Unix for you. Perl programs that actually do anything useful are notor-iously hard to decipher into English, but then it was designed to be easy to write, not easy to read.

The relationship between computer languages and English is fascinating and immensely complicated, but last week an American court, whose decisions cover roughly the West Coast, decided that computer code was speech and so protected under the first amendment. They had been asked to adjudicate on this point because there are some fragments of code that are classified by the American government as munitions and so may not be exported without a permit, or posted on the Internet without permission.

These are the code snippets that demonstrate how to encrypt documents (or anything) so that they cannot be read without the proper key. This knowledge is classified by the American government as a weapon. If you demonstrate these tricks in source code, as a teacher must, then you are - in the nature of the Internet and of source code - simultan-eously exporting what you demonstrate. As a human, I can read the stuff and slowly puzzle out what it does; but if I feed it into the right program on my computer, it will simply translate it into machine instructions and do it all at once.

It's an unfortunate confusion that "source code", in the sense of the language understood by computers, sounds as if it has something in common with encryption. It does not. Encryption is a way of using mathematical tricks to conceal things. Computers have made possible both the cracking of old-fashioned ciphers, like those used in Enigma, and the construction of new, entirely unbreakable ones, which are those the US government tried to control. Some reasons for this are admirable. Strong crypto, as it is called, could make life easier for anyone who wishes to conceal their doings from the government, including all manner of terrorists, paedophiles, neo-Nazis and so on - though it has to be said that there is very little evidence that it has actually been used in this way yet. But it is essential if the Internet is to become a safe place on which to ship money and secrets about, and the technology can also be used to lock up digital music or any other software so that it can be used only by authorised people.

Since there are such huge sums of money to be made, potentially, by the use of strong crypto, it looks as if the struggle to contain it will eventually be lost. The difficult thing to understand, though, is why it should have been fought so hard and so long, when the mathematics of strong encryption are no secret and the code necessary to do the job has been freely available since 1986 at least. One answer is provided by a report for the European Parliament released last week on the huge resources devoted by the American National Security Agency (and its virtual subsidiary GCHQ) towards intercepting electronic communications and analysing them using enormous computing resources.

The report is a paranoid's dream. About the only thing that the Echelon system, as it is known, cannot do is automatically scan voice telephone calls for particular words. Speech-recognition technology is not up to it yet. On the other hand, voice prints can be reliably and automatically identified, so that any calls made by a particular person can be hunted down, recorded and listened to.

E-mail is even more easily intercepted. Because of the way the Internet works, there is a fairly high likelihood that even messages sent within Europe will pass through some of the main Internet routers in the USA, and there is some evidence to suggest that all these routers have been wired up by the NSA so that it can pick out messages of interest. What is certainly true is that it remains illegal for American companies to sell for export e-mail software that is capable of encryption and that might trouble the NSA, and it's hard to see why that should be the case if they didn't have access to the messages so falsely encrypted.

This kind of thing gets many people hugely excited; if you want to be among them, seek out the original of the Echelon report at Afterwards, you may conclude that the discovery of yet another secret committee spying on us is more or less business as usual, and follow Sharon Hopkins' advice instead:

read (books,poems,stories) until peaceful;