How does your "Yes" wash with the next paragraph of your note?

I'm sorry. My answer was misleading (read 'wrong'). What I was trying to say was: "Yes, but not in a reasonable amount of time." My implication was that an attack against RSA with a 1264 bit key and an attack against IDEA with a 128 bit key are both prohibitive, but that my _guess_ is that cryptanalysis of the IDEA cypher would be the more fruitful attack. If the real question is: "Am I safe from the NSA when I use PGP and encrypt with a 1264 bit key?" Then I must answer: "In my opinion, you are reasonably safe." If the question is:

Could the NSA reverse PGP encryption on a message that was encrypted with a 1264 bit key?

Then I must answer: "Yes, it is mathematically possible; although unlikely in the extreme." I apologize.

Sorry I didn't include more numbers,

...really sorry. They said what I meant.

And IDEA is not susceptible to diff.cryptan - that's the way it was *designed* (actually the designer proved mathematically the invinsibility of IDEA to this attack).

Thanks for this info. I have been trying to get the IDEA papers: "Detailed Description and a Software Implementation of the IPES Cipher" "Markov Ciphers and Differential Cryptanalysis" without success, as yet. Perhaps you have them or know of an ftp site? Thanks, Scott Collins | "Few people realize what tremendous power there | is in one of these things." -- Willy Wonka ......................|................................................ BUSINESS. voice:408.862.0540 fax:974.6094 collins@newton.apple.com Apple Computer, Inc. 1 Infinite Loop, MS 301-2C Cupertino, CA 95014 ....................................................................... PERSONAL. voice/fax:408.257.1746 1024/669687 catalyst@netcom.com