After spending millions and even more into software that would protect the computers from vicious attacks with ever new viruses, loggers and whatnot, the simplest method is the one that works best, provided access to the PC is granted. It's simple and everybody can do it, but only somebody more experienced can actually capitalize on the possibility.

According to a research conducted at Princeton University, the easiest and most certain way to hack a computer is to blast it with a burst of cold air. This will change the way the memory chip works and instead of erasing information within seconds, the gush of air will cause the DRAM chip to retain it for minutes and even hours after the machine loses power.

Rebooting the hacked PC with a program that copies the memory contents is all it takes, and voila, all the bank accounts and passwords are a giveaway, not to mention the rest of the content of the hard drive. According to other polls and common sense, the most computers stolen are laptops, and if they are not shut down when they are taken and instead are in hibernate or sleep mode, they will be even more vulnerable.

"These risks imply that disk encryption on laptops may do less good than widely believed. [...] Ultimately, it might become necessary to treat DRAM as untrusted, and to avoid storing sensitive confidential data there, but this will not be feasible until architectures are changed to give software a safe place to keep its keys," according to the report, which was published last week by researchers from Princeton, Wind River Systems software company and the Electronic Frontier Foundation digital rights group.

The temperature required for this to work, the study showed, was of -50 degrees Celsius, or about -60 degrees Fahrenheit.