[207] in cryptography@c2.net mail archive
Re: RC4 keysearch
daemon@ATHENA.MIT.EDU (Arnold G. Reinhold)
Mon Feb 10 11:55:28 1997
In-Reply-To: <MAPI.Id.0016.00656c73657920203237433630303030@MAPI.to.RFC822>
Date: Mon, 10 Feb 1997 09:43:55 -0400
To: kelsey@email.plnet.net
From: "Arnold G. Reinhold" <reinhold@world.std.com>
Cc: cryptography@c2.net
John Kelsey suggests:
>
>There are a few obvious speedups available for RC4 keysearch.
>For example, if you have an implementation that does
>real_key = salt || short_key with an 11-byte salt and a 5-byte
>key, then an attacker can tackle the first 11 bytes of key
>scheduling once, and have all processors start from there.
I do not believe this can be done with RC4 to any significant extent. The
key scheduling step requires all the key bits together.
Arnold Reinhold
