A lot has been debated about user identification with reference to security issues as computers have been used extensively in terror related incidents. In what could be a breakthrough, bacteria can reveal the identity of the user. Scientists at the University of Colorado at Boulder have found that the bacteria trail left behind on objects like computer keyboards and the mouse can analyzed and used to help identify users of those devices.

Noah Fierer, Assistant Professor, CU-Boulder and his colleagues have demonstrated that the distinctive combination of bacteria each of us carries and distributes can be used to help identify what we have touched. This finding will help link individuals to malicious computer use or other crimes. 'Forensic identification using skin bacterial communities,' the study which appeared in the Proceedings of the National Academy of Sciences, describes how the researchers swabbed bacterial DNA from the keys of three personal computers and matched them to the bacteria on the fingertips of the owners of the keyboards. It also details a similar test conducted on computer mice that had not been touched for over 12 hours.

The study indicates that the technique is 70 percent to 90 percent accurate and Fierer expects that accuracy will improve as the technique is refined. Until accuracy is extremely high, the technique is most likely to be useful as a way to augment more established forensic techniques, like fingerprinting and DNA identification.

Among other methods of user identification, keystroke analysis has been used to a certain extent. However, unlike other access control systems based on biometric features, keystroke analysis has not led to techniques providing an acceptable level of accuracy. The reason is probably the intrinsic variability of typing dynamics, versus very stable biometric characteristics, such as face or fingerprint patterns.