From: Bill Sommerfeld <sommerfeld@orchard.medford.ma.us>
Date: Wed, 9 Aug 95 21:48:01 PDT
To: Hal <hfinney@shell.portal.com>
Subject: Re: "S1" encryption system
In-Reply-To: <199508092310.QAA11567@jobe.shell.portal.com>
Message-ID: <199508100443.EAA00611@orchard.medford.ma.us>
MIME-Version: 1.0
Content-Type: text/plain


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BTW, I compiled it and confirmed that decryption is the inverse of
encryption for at least one (key, plaintext) pair..

> BTW I just was starting to look at the key scheduling and I noticed that
> fullkey is indexed in its 2nd slot by i*2 where i goes from 0 to 31, but
> is only declared as being 32 in size in that slot.  So I think this is
> another typo, probably the index should be i.  This kind of thing does
> not inspire confidence...

It looks very much like the sort of typo you would get from a
mistranslation from assembly language if the target architecture had a
*4-bit* processor. (This is also consistant with the "<<4"'s which
show up in several places in the code).

The typo is consistant -- it shows up every time the key schedule is
referenced; it looks like a semi-mechanical translation was done..

					- Bill

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