On Thu, 29 Nov 2007 16:05:00 -0500 "Tim Dierks" <[EMAIL PROTECTED]> wrote:
> A random thought that's been kicking around in my head: if someone > were looking for a project, an open-source permissive action link ( > http://www.cs.columbia.edu/~smb/nsam-160/pal.html is a good link, > thank you Mr. Bellovin) seems like it might be a great public > resource: I suspect it's something that some nuclear states could use > some education on, but even if the US is willing to share technology, > the recipient may not really trust the source. > > As such, an open-source PAL technology might substantially improve > global safety. > I don't think it would be fruitful. Have a look at page 2 of http://www.nytimes.com/2007/11/18/washington/18nuke.html -- it notdes that "The system hinges on what is essentially a switch in the firing circuit that requires the would-be user to enter a numeric code that starts a timer for the weapon?s arming and detonation." I don't think that that's quite correct -- it permits arming; PALs are not in the firing circuit, I believe -- but this section is more interesting: "Delicate design details involve how to bury the link deep inside a weapon to keep terrorists or enemies from disabling the safeguard." In other words, it's easy to have a circuit that keeps the bomb from arming; the hard part is doing so with high assurance against attacks, and that's very design-dependent. --Steve Bellovin, http://www.cs.columbia.edu/~smb --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]