Computer scientists at the University of Michigan have found a major flaw in a most common digital security technique used to protect both media copyright and Internet communications.

The experts claim that they could foil RSA authentication system by varying the voltage supply to the holder of the "private key," which would be the consumer's device in the case of copy protection and the retailer or bank in the case of Internet communication. RSA authentication is a popular encryption method used in media players, laptop computers, smartphones, servers and other devices.

 

Experts were able to extract the private key in approximately 100 hours using their voltage tweaking scheme, even though the private keys contain more than 1,000 digits of binary code. It was found that varying the electric current stresses out the computer, which ends up making small errors in its communications with other clients.