Artificial immune systems

How our body's defences aid computers in distress

Most such approaches so far have tended to mimic the way the white blood cells of the immune system watch out for molecules that are not "self", such as proteins made by viruses, bacteria and parasites. These approaches used software to police the network in a similar way. However, in computer systems this tactic means dangerous activity can be overlooked if it appears legitimate, such as a virus disguised as an ordinary email.

The Nottingham team's approach is instead based on an alternative model of how the immune system works, called danger theory. According to this, the immune system does not attack foreign molecules whenever it detects them, but only if they start to cause trouble, says Julie McLeod, an immunologist at the University of the West of England in Bristol.