1996-04-09 - Re: RC4 improvement idea

Header Data

From: “Perry E. Metzger” <perry@piermont.com>
To: nyap@mailhub.garban.com (Noel Yap)
Message Hash: 91dae13f5d072f5d4318fe3462c392e5dac9fb942beb72a6e14484588db0061b
Message ID: <199604090017.UAA28573@jekyll.piermont.com>
Reply To: <9604082133.AA15440@mailhub.garban.com>
UTC Datetime: 1996-04-09 06:25:46 UTC
Raw Date: Tue, 9 Apr 1996 14:25:46 +0800

Raw message

From: "Perry E. Metzger" <perry@piermont.com>
Date: Tue, 9 Apr 1996 14:25:46 +0800
To: nyap@mailhub.garban.com (Noel Yap)
Subject: Re: RC4 improvement idea
In-Reply-To: <9604082133.AA15440@mailhub.garban.com>
Message-ID: <199604090017.UAA28573@jekyll.piermont.com>
MIME-Version: 1.0
Content-Type: text/plain



Noel Yap writes:
> The S-Boxes in DES were optimized to hinder Differential
> Cryptanalysis.  I've seen no studies on the effectiveness of
> jumbling the S-Boxes during encryption -- even Biham and Shamir's
> book doesn't mention it -- but, I figure, if it helps, DES would
> probably already be doing it (unless of course the NSA thought the
> jumbling would make too good an algorithm).

Your conclusion may be correct, but your reasoning is faulty. DES was
built to be run in hardware, which doesn't make S-Box jumbling easy;
it was in fact built to be run on the hardware of twenty years ago,
which was far more constrained than our hardware is now.

Perry





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