Encryption Expert Sees "Serious Flaw" in Microsoft Programs

Cryptography expert Phil Zimmermann has said he believes the flaw discovered in Microsoft's Word and Excel encryption is serious and warrants immediate attention. "I think this is a serious flaw -- it is highly exploitable. It is not a theoretical attack," said Zimmermann, referring to a flaw in Microsoft's use of RC4 document encryption unearthed recently by a researcher in Singapore.