Re: A hole in esp-stream-01

Germano Caronni <caronni@tik.ee.ethz.ch> Tue, 29 October 1996 22:19 UTC

From: Germano Caronni <caronni@tik.ee.ethz.ch>
Message-Id: <199610292224.XAA08726@kom30.ethz.ch>
Subject: Re: A hole in esp-stream-01
To: JMKELSEY@delphi.com
Date: Tue, 29 Oct 1996 23:24:46 +0100
Cc: ipsec@TIS.COM
In-Reply-To: <01IB31SYGDLU8ZINVB@delphi.com> from "JMKELSEY@delphi.com" at Oct 26, 96 03:36:33 am
Content-Type: text
Sender: ipsec-approval@neptune.tis.com
Precedence: bulk

JMKELSEY@delphi.com wrote:
> Now, remember, we turned the high bit off in the ciphertext byte,
> and on in the plaintext byte.  What this means is that we subtracted
> 128 from the ciphertext byte, and added it back in the plaintext
> byte.  Thus, (C[4]* + P[4]*) = (C[4] + P[4]).
> 
> If we have to also deal with the CRC of this, so long as the CRC
> polynomial is known, we can just flip the bits that would have
> changed in the CRC, right?

Right. Consider my proposals to 'fix' esp-stream as retracted. It either has
to be a real (fast) MAC, or a note in the 'Security Considerations'. What do
you people prefer?

Germano

A hole in esp-stream-01 Germano Caronni
Re: A hole in esp-stream-01 JMKELSEY
Re: A hole in esp-stream-01 JMKELSEY
Re: A hole in esp-stream-01 David Wagner
Re: A hole in esp-stream-01 Germano Caronni
Re: A hole in esp-stream-01 Germano Caronni
Re: A hole in esp-stream-01 Germano Caronni
RE: A hole in esp-stream-01 Andrew Robison
Re: A hole in esp-stream-01 Germano Caronni
RE: A hole in esp-stream-01 Andrew Robison