Dr. Richard Carrigan, a particle physicist at the US Fermi National Accelerator Laboratory in Batavia, Ill., said efforts to decode signals from space by means of programs such as Seti@home could leave computers running the software open to attack from alien viruses.
Signals picked up by the Seti (Search for Extraterrestrial Intelligence) project, based at the University of California at Berkeley, are distributed through the internet to users running a screensaver that decode chunks of that signal in search of extra-terrestrial life. Carrigan, in a recent scientific paper presented at the 54th International Astronautical Congress, believed that there is a small chance that a signal could harbor alien malware if not checked first.
The idea of an alien "SETI hacker" is not new - many science fiction writers have explored the possibility. But with new technology to decode signals into possibly usable data, Carrigan said it was time to look at ways to "denature" or clean up SETI signals.
"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," said Carrigan.
Others believe the threat is not significant.
"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, Cal., told science magazine space.com.
Shostak said there was no need to worry about alien viruses as all SETI radio experiments averaged out signal losing "any high-information content message".
"This signal averaging is like a microbe filter, screening them (alien viruses) out!" he said.