Microsoft may have to fork up big bounty bucks trying to unearth future hackers, particularly when they are light years away on distant worlds.

Add one more worry to the computerized world of the 21st century. Could a signal from the stars broadcast by an alien intelligence also carry harmful information, in the spirit of a computer virus? Could star folk launch a "disinformation" campaign -- one that covers up aspects of their culture? Perhaps they might even mask the "real" intent of dispatching a message to other civilizations scattered throughout the Cosmos.

These are concerns that deserve attention explains Richard Carrigan, Jr., a physicist at the Fermi National Accelerator Laboratory in Batavia, Illinois. Those engaged in the Search for Extraterrestrial Intelligence (SETI), he contends, should think about decontaminating potential SETI signals.

The so-called "SETI Hacker" hypothesis, Carrigan argues, is an issue of interstellar discourse that should be taken seriously. We should exercise caution when handling SETI downloads, he said.
Altruistic, benign, or malevolent?

Carrigan notes that Earth's early radio ramblings have already traveled some fifty light years away. (A light year is the distance that light travels in a vacuum in one year, equal to 5.88 trillion miles (9.46 trillion kilometers).

Turns out that on the order of 400 stars are within 50 light years of Earth. Any civilization out at that distance may have immediately responded and sent a signal back to Earth. "Such a signal could be useful or possibly very harmful to us," Carrigan suggested in a recent scientific paper presented at the 54th International Astronautical Congress, held September 29th - October 3 in Bremen, Germany.

A key question is whether or not a SETI signal might be altruistic, benign, or malevolent. "It would help to understand the motivation of a message before reading too much of it," Carrigan said. Like Odysseus of Greek Mythology, he added, "we may have to stuff wax in the ears of our programmers and strap the chief astronomer to the receiving tower before she is allowed to listen to the song of the siren star."

Message impact

The SETI Hacker concept is not new. It has been fodder for science fiction writers over the years. But today, given the reality of scanning the heavens for other advanced civilizations, it's time to take an analytical look for means to "denature" SETI signals, Carrigan proposes.

New and exciting efforts like the SETI Institute's Allen Telescope Array, for example, will allow a targeted SETI search to proceed 24 hours a day, 7 days a week. This new instrument is a joint effort by the SETI Institute and the University of California, Berkeley. Because of its novel construction -- an array of inexpensive antennas -- it can be simultaneously used for both SETI and cutting-edge radio astronomy research.

"That facility is powerful and ratchets up the possibility of an extraterrestrial intelligence detection by large factors. I hope that well before the facility goes into serious operation there can be a "messages and message impact" workshop of technical people, non-SETI experts in computers, languages, signaling, etc.," Carrigan told .

The character and size of an ET signal will shape the approach to treating the signal content. Say that we're on the receiving end of a beacon with a message of less than a hundred kilobytes repeating every 10 seconds or so. That could be handled without too many precautions, Carrigan said.

Electronic condom

But for some SETIologists, there is the hoped for prospect of tapping into some type of galactic Library of Congress. Carrigan notes that a signal from the stars will have to provide some attractive "advertisement" or lure to enlist the help of a host. Almost certainly, he adds, actual messages will have gone through some sort of compression.

"The signal will have to carry the compression decoding algorithms embedded in the message. On a first level it is to the advantage of the sender to have the compression algorithm totally clear," Carrigan said. The message size can easily be so large that the underlying intent of the message would not be apparent, he said.

Striking the motherlode of SETI speak, however, could cause an overload -- an inability on our end to handle oodles of information. "Even an advanced civilization might have to draw the line somewhere on the scale of message transmission," Carrigan pointed out.

Yet even a beacon could point to a signal in a different wavelength band where a message was coming in. "A message should be approached with great care. It may be extremely dangerous," Carrigan warns. "Put simply, the receiver needs virus protection."

Code of behavior

Ultimately, what may be needed is a protocol similar to the one for biological contamination of a probe returning from space -- like that discussed in handling surface materials brought back from Mars. The prospect of a virulent microbe from Mars doing damage to Earth's ecosystem cannot be dismissed.

Those engaged in SETI work have already hammered out a protocol to follow if any ET signal is detected. But that code of behavior is more meant to avoid public relation problems if a signal is announced prematurely, Carrigan said.

"The possibility of a malevolent SETI Hacker signal must be assessed and protective measures should be put in place prior to the receipt of any real signals," Carrigan advises.

Look at the big picture

Is there a serious "threat" here?

"I think Carrigan makes an interesting suggestion. I don't think that there's much to worry about, however," said Seth Shostak, Senior Astronomer at the SETI Institute in Mountain View, California.

To begin with, Shostak said, all radio SETI experiments "average" incoming signals for seconds or even minutes. This means that any high information-content message is smoothed away...and lost, he said.

"No need to worry about alien viruses infecting our machinery," Shostak added, "because this signal averaging is like a microbe filter, screening them out!" For optical SETI experiments -- looking for flashes of laser-carried chatter from ET -- this is less true, as these searches could, in principle, rather easily record a large series of "ones and zeroes" that might be sent our way on a beam of light, Shostak told .

Shostak said that you've got to look at the big picture.

"I don't think that, given the likely -- and large -- difference in technological level between transmitting extraterrestrials and us, that we would be suitable targets for either malicious infections or attempts to 'beam themselves here,'" Shostak said.


The wise make mistakes, the fools repeat them
When you have eliminated the impossible, that which remains, however improbable, must be the truth