From: doug@netcom.com (Doug Merritt)
Date: Tue, 12 Oct 93 21:09:58 PDT
To: cypherpunks@toad.com
Subject: Re: Breaking DES
In-Reply-To: <pmetzger@lehman.com>
Message-ID: <9310130408.AA24361@netcom5.netcom.com>
MIME-Version: 1.0
Content-Type: text/plain


Thank you, Perry, for some good comments that were flame-free. I
personally appreciate that, especially considering that your comments
are both apropos and good food for thought.
	Doug

>pmetzger@lehman.com said:
>Karl Lui Barrus says:
>> So maybe it's only of theoretical interest, sort of like differential
>> cryptanalysis against the DES - which requires 10^47 chosen
>> plaintexts.
>> 
>> Why don't you mail Biham and Shamir that their method sucks.  It's
>> fairly infeasible as well.
>
>It *IS* infeasable, and they realize it. The breakthrough was
>differential cryptanalysis itself, and the discovery that DES was
>fairly resistant to it. The fact that they made ANY crack in it was
>kind of neat, by the way.
>
>A huge number of chosen plaintexts is of course pretty much not
>possible in practice, especially since you might not get any chosen
>plaintexts at all!