04 August 2006
SETI League
PriUPS Project


Empty Spam & Numbers Stations

40243 07527 09112 87454 33401 81760

Neither you nor the NSA will ever decode the "message" above.  That's because there is no message.  It's just my spastic fingers pressing some keys at more-or-less random.  But there are, or at least were, short wave radio stations transmitting sequences of numbers like these day and night.  Although I don't think anything "official" has ever been revealed about them, it is almost certain that they are (or were) transmitting information or orders to intelligence agents (spies) in the "field."   Why go to all this trouble?

  • Because they are "broadcast," there's no way to determine for whom the messages are intended.  In fact, many hobbyists listened to them, presumably innocuously.

  • Unless, in the unlikely event they were encoded with something other than a "one time pad," the messages are both practically and theoretically unbreakable.  

But!  They require the recipient to have a shortwave radio, in itself a suspicion-arousing accoutrement in some countries and under certain circumstances.

Spam - The New Numbers Stations

I am an accomplished and prolific spammee.  I receive over a thousand spams every day, and I've gotten to the point of identifying and erasing them in milliseconds.  Because I do this without actually looking at the message body, I missed an interesting trend, characterized as "empty spam" in an article in the Wall Street Journal. 

Sometimes known as "empty spam," the persistent strain of junk mail has been puzzling millions of consumers in recent weeks.  These emails, unlike standard spam, contain no perceptible marketing offers, viruses, or requests for personal information.  They are just blocks of text, often lifted from classic literature.

The article goes on to speculate about its purpose.  One suggestion is that it is designed to throw off spam filters and reduce their ability to stop real spam.  Another is that they are simply a miscommunication between "zombie" computers and their controllers.

But what if it's something else?  Even before the WSJ called my attention to this new format, it had occurred to me that spam was an almost ideal way to communicate with spies.  "Steganography" is the art of hiding messages in other messages.  For example, if you have a photograph, you can encode a text message in the least significant bits of successive pixels.  Even in this simplistic form it would be invisible and difficult to find by a lay person.  With some care the message can simulate noise so effectively that it is almost impossible to find.  But it would still require that the intended recipient go to a web site to see it, which might be traceable.  Or, if the picture was part of a spam, it would presumably have to be meaningful on some level or it would arouse the suspicion of the agencies monitoring such things.  But if the picture were, for example, a sales pitch, people might act on it, and the CIA (or whomever) would have to supply Viagra or get sued for consumer fraud.

Is not, then, an "empty spam" the perfect solution for agent communications?

  • It is sent to a million people or more people at once - there's no way to identify the one for whom it bears special significance.

  • Because there's no apparent message content it will be ignored.

  • Everybody has a computer, and everybody gets spam.  No telltale shortwave radio.

Of course there must be a message hidden in the text, whether by misspellings, word substitutions, odd line breaks, the random garbage put in the Subject line to entice one to open it, or, most likely, a combination of them all.  Even if the NSA can trace the origin of the message, it's unlikely to be able to decode it, and certainly won't be able to determine the recipient.

I wonder which of my thousand daily spams is made of spy stuff!

Richard Factor