http://www.nytimes.com/2008/02/22/te...22chip.html?hp
Princeton researchers have discovered a new way to compromise the encryption on hard drives: Freeze the RAM chips.
Although it's widely assumed that the information in dynamic random access memory (DRAM) chips is erased as soon as a computer is shut down, researchers have discovered that these chips can retain their info anywhere from a few seconds to a few minutes. A blast of cold air, such as what is available in cans of compressed air used to clean keyboards allows these chips to retain their memory even longer.
Princeton researcher Edward Felton: “Cool the chips in liquid nitrogen (-196 °C) and they hold their state for hours at least, without any power. Just put the chips back into a machine and you can read out their contents.”
Once the memory is retained, these chips can be installed into computers that use pattern recognition software to identify the encryption keys and break the encryption of a hard drive.
Princeton's method of decryption was successfully demonstrated on computers that used Microsoft Windows, Macintos OS, Linux operating systems.
All kinds of secret squirrel stuff is out there.