[87703] in Cypherpunks
Re: Quor's cipher
daemon@ATHENA.MIT.EDU (Matthew Ghio)
Sun Oct 5 15:11:58 1997
Date: Sun, 5 Oct 1997 14:43:42 -0400
To: cypherpunks@cyberpass.net
From: ghio@temp0130.myriad.ml.org (Matthew Ghio)
Reply-To: ghio@temp0130.myriad.ml.org (Matthew Ghio)
Antonomasia <ant@notatla.demon.co.uk> wrote:
> How are you planning to detect which bytes are passed in this way ?
> Chosen plaintext attacks would do it, and show where (a+b)^(a0+b0) == 0.
> Looks like you've just doubled our progress.
It doesn't take chosen plaintext, just known plaintext.
>
> If the key is reused with a different message I don't think there's a
> weakness. An IV is a good idea, but aren't we _attacking_ this thing ?
Lack of an IV is a problem with almost any cipher, but it seems especially
so here.
