30 March 1998

To: cryptography@c2.net
Subject: cryptography and permissive action links
Date: Sat, 28 Mar 1998 22:35:41 -0500
From: Steve Bellovin <smb@research.att.com>

Several months ago, following the release of the British papers on
their early work on public key cryptography, and my posting of NSAM-160,
a brief discussion started on how permissive action links work, and
how they secure nuclear weapons.  Since then, I've done a fair amount
of reading and research on the subject.  I've written up what I've
learned; see http://www.research.att.com/~smb/nsam-160/pal.html if
you're interested.