Using a previously recorded or captured message to attack a computer system or network or to gain access to somewhere one is not authorized to be (a form of identity theft). Many people consider biometrics to be a very secure means of authentication and a rather effective means of fighting off a replay attack. However, the 1983 movie War Games showed how someone can fool cryptographic systems if the systems are created in a naïve and vulnerable manner. For example, a cracker can record an authorized person’s voice and replay it in order to access a system. This replay attack can be enhanced if the cracker uses digitalized information. The 1997 movie Gattaca showed how even more sophisticated DNA-based computer security systems could be fooled. The movie tells a futuristic story about a genetically imperfect man who has an unrequitable need to travel in space, so he takes on the identity of an athlete who is genetically able to pursue the dream.

See Also: Cracker; War Games of 1983.