The evil in e-mail

By watching for certain keywords, law enforcement agencies can already identify e-mails that might contain clues to criminal activity and corporations can flag employee messages that could cause legal problems.

Keywords have limitations, though – people trying to avoid detection may steer clear of language likely to attract attention. So a Queen's University researcher is exploring ways to spot suspicious e-mails even when writers try not to give themselves away.

Dr. David Skillicorn's work is based on the idea that when people are trying to hide something, they write differently than people who have nothing to hide. That's more true of e-mail than of more formal documents, he adds, because few of us go back and edit our e-mails.

A related trick, he says, is to examine patterns in who e-mails whom. As an example, in criminal networks it is common to find several people communicating regularly with the same person, but never with each other. This is meant to ensure that if one lawbreaker is caught, he or she is unlikely to lead authorities to too many others. But it can also be a clue to suspicious activity.