From: Carl Ellison <cme@TIS.COM>
Date: Fri, 11 Aug 95 14:24:45 PDT
To: hfinney@shell.portal.com
Subject: Re:  More "S-1" foolishness
In-Reply-To: <199508111809.LAA02095@comsec.com>
Message-ID: <9508112119.AA13790@tis.com>
MIME-Version: 1.0
Content-Type: text/plain


>Date: Thu, 10 Aug 1995 20:53:58 -0700
>From: Hal <hfinney@shell.portal.com>
>
>The other thing I noticed that really makes me question this is that G1
>only uses 4 of its 8 input bits.  As I wrote, it is equivalent to
>parity(i&0x17).  A bit is a terrible thing to waste, and it is hard to
>imagine why it would do this intentionally.  G1 may not be that important
>an element of the cipher but why throw away four bits?

Not that I say this is real, but...

I can maybe understand throwing out 4 of the bits if G0 picks them up.  G1
is never used alone.

However, has anyone already noted that

	fullkey[INTEGRITY][i][j] = 0x08 ;

for all i and j?

For that matter, fullkey will be a constant for any key with all the bytes
the same.  This might constitute a class of weak keys.


 - Carl