Computer attack

A team of academics from Princeton University has demonstrated a new class of computer attacks that compromise the contents of 'secure' memory systems, particularly in laptops.

The attacks overcome a broad set of security measures called 'disk encryption,' which are meant to secure information stored in a computer's permanent memory. The researchers cracked several widely used technologies, including Microsoft's BitLocker, Apple's FileVault and Linux's dm-crypt, and described the attacks in a paper and video published here.

The attacks are particularly effective against computers that are turned on but are locked, such as laptops that are in a 'sleep' or hibernation mode. One effective countermeasure is to turn a computer off entirely, though in some cases even this does not provide protection.

The new attacks exploit the fact that information stored in a computer's temporary working memory, or RAM, does not disappear immediately when a computer is shut off or when the memory chip is taken from the machine, as is commonly thought. Under normal circumstances, the data gradually decays over a period of several seconds to a minute. The process can be slowed considerably using simple techniques to cool the chips to low temperatures.