From: frantz@netcom.com (Bill Frantz)
Date: Mon, 11 Mar 1996 10:23:20 +0800
To: cypherpunks@toad.com
Subject: Re: TCP/IP Stego (was CU-SeeMe)
Message-ID: <199603082056.MAA20781@netcom7.netcom.com>
MIME-Version: 1.0
Content-Type: text/plain


At 12:19 PM 3/8/96 -0800, Jim McCoy wrote:
>... The original
>technique of doing stego on packets is still valid, and by adding it in
>to a WinSock lib or linux tcp/ip implementation the user can send hidden
>messages just by connecting to a friendly stego-enhanced web server out
>on the net and doing some casual browsing.

If you can hack your TCP implementation, you should be able (with a high
probability) stego information in a few bits of the TCP checksum by
adjusting the packet boundries of the TCP stream.  An error correcting code
protocol would cover the cases where you couldn't get that *%$# bit set
correctly.  Please note that this technique would not result in TCP
checksum errors.


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