"Cool the chips in liquid nitrogen (-196 °C) and they hold their state for hours at least, without any power," Edward W. Felten, a Princeton computer scientist, revealed.

Solution:
Austin Wilson, director of Windows product management security at Microsoft - use BitLocker in some cases with additional hardware security, that might include either a special U.S.B. hardware key, or a secure identification card that generates an additional key string.

Apple - security of the FileVault system could be enhanced by using a secure card to add to the strength of the key.