From: Andrew Loewenstern <andrew_loewenstern@il.us.swissbank.com>
Date: Fri, 8 Dec 95 19:08:51 PST
To: "Rev. Mark Grant" <mark@unicorn.com>
Subject: Re: Still more on the Digicash protocol
Message-ID: <9512082354.AA02244@ch1d157nwk>
MIME-Version: 1.0
Content-Type: text/plain


David A Wagner writes:
> >Tough!?  It's trivial for an active attacker, in the stream cipher case.
> >He just xors some bits: no clever cryptanalysis needed.  (Or did you mean
> >it's tough to mount an active attack?  I agree: that requires significant
> >knowledge or motivation.)
Rev. Mark Grant responds:
>  Exactly.. once you have an active attack set up, it's trivial, but
>  setting that up is quite hard.

But setting up an active attack is probably a hell of a lot easier than  
breaking 128-bit RC-4 (or even 64-bit).

andrew