Cryptologists Discover Flaw in E-Mail Security Program
If confirmed, the flaw would allow a determined adversary to obtain secret codes used by senders of encrypted e-mail.

The program, called P.G.P. for Pretty Good Privacy, is used by human rights organizations to protect vulnerable sources, by corporations to ensure secure communications and by millions of individual users.
http://www.nytimes.com/2001/03/21/technology/21CODE.html?pagewanted=all