# [rc5] key block

Wed Aug 27 12:38:09 EDT 1997

```> Date:          Wed, 27 Aug 1997 11:03:40 +0200 (MET DST)
> From:          Ivo Janssen <ivo at ricardis.tudelft.nl>
> To:            rc5 at llamas.net
> Subject:       Re: [rc5] key block

> On Tue, 26 Aug 1997, Costin RAIU wrote:
>
> > > i bet the correct key will be found in the last place we look.
> >
> > Let's hope not ! Anyway, one could expect the key to show up when  86%
> > of keyspace is complete :)
> > (14% for the DES, so 50-14=36 50+36=86
> > so 86 is required to restore the probabilistic balance)
>
> Well, actually there is a 50% change that we will find the key when
> 86% is complete. Either we find it there or we don't.

I have a 50% chance of winning the lottery.  Either I win, or I
don't.

(hrm..wait a sec..that doesn't sound right!)

>
> But then again: There's also a 50% change that we could have found
> it in the first 15% percent of the space. Again: either we find it
> or we don't.

No, there's a 15% chance that we'd find it in the first 15% of the
keyspace.  Funny how these percentages things work.

>
> So: 50% for 86% complete and 50% for 15% complete. That makes a
> total of 100%. And we know we didn't find it in the first 15
> percent, so now we know for sure that we will find the key when
> we've done 86%.

Wait a sec...then there was a 50% chance of finding it when it was 1%
complete, added to the 50% chance of finding it when it was 2%
complete...why haven't we found it yet..i'm soooo confused.  I think
we should find it at 24%, because that's where we found it last time,
and I've found that when I lose my keys..I usually lose them in the
same place.

>
> I suggest that Bovine distributes key "DC28F5:C28F15C0" and we have
> won!!!!!!!!!!!!!!
>
> Ivo
>
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Brian Murphy
Network Engineer