Adi Shamir, who is the S in RSA, has presented material at the Crypto 2008 conference that has promised a new form of mathematical attack against a broad range of cryptographic ciphers, including hash functions (such as MD5, SHA-256), stream ciphers (such as RC4), and block ciphers (such as DES, Triple-DES, AES).

Normally, unpowered DRAM memory chips lose their contents after a several seconds. But a team of researchers have discovered if those chips can be kept very cool, then they might retain their contents for up to an hour or more. According to the researchers’ findings, that gives someone plenty of time to read the memory in the chips and recover a user’s encryption keys.