Subject: Re: Next Steps

From: [email-masked] ("Hal Finney")
Date: Tue, 6 Nov 2007 14:18:22 -0800 (PST)

I would be very cautious about using RC4. Every year it seems to get
weaker. In the past year alone there have been four new attacks on it
published on the eprint.iacr.org servers: 2007/305, 2007/261, 2007/208,
and 2007/070. I would not be at all enthusiastic about putting it into
OpenPGP.

I wonder if there is some better-vetted cipher which would be faster
than AES, that might be usable. I'd also look into whether there might
be an AES implementation that is better optimized for ARM (or whatever
the processor is).

Hal Finney
PGP Corporation

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From: Jon Callas <[email-masked]>
Date: Tue, 6 Nov 2007 15:09:55 -0800

> and 2007/070. I would not be at all enthusiastic about putting it into

Yes, but there are also ways that you can use RC4 to make it safer. I  
think that if there were an RC4 draft that had those things taken  
into account, it might be okay. This has the drawback of having  
OpenPGP having *another* eccentricity in its crypto use, but there's  
a good reason for the eccentricity.

I'm willing to look at a sketch of how it could be made safe.

	Jon