Re: Still more on the Digicash protocol

[Andrew Loewenstern <andrew_loewenstern@il.us.swissbank.com>]

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