Re: DC Setiathome group?

[InfoSec News <isn () c4i org>]

OK, its a fun read and a great flame.

Enjoy!

- WK



---------- Forwarded message ----------
Date: Sat, 28 Jul 2001 03:37:51 -0400
From: Izaac <izaac () setec org>
To: Jeremiah Gowdy <jgowdy () home com>
Cc: dc-stuff () dis org
Subject: Re: DC Setiathome group?


On Fri, Jul 27, 2001 at 08:30:46AM -0700, Jeremiah Gowdy wrote:
> As I said in another flame, there is a $2,000 prize which I theoretically
> have a 1 in 17,000 chance of winning.  Not bad odds.

Alright, fuckwit. I just got home after an hour stuck on the subway.
I'm tired.  I'm cranky.  And I've got zero tolerance for stupidity.
Here we go.

I'm going to presume that you're participating in the
'distributed.net' RC5 cypher challenge[1].  You're brute forcing a
2^64 key space.  A somewhat daunting task.  But Linux Losers of the
World, UNITE!  We'll waste plenty of cycles attempting to accomplish
the irrelevant.

   Key space          = Ks = 2^64 ~= 18.447*10^18 k

According to their statistics page[2], which is little more than a
couple graphs from which numbers are a real pain to pull (and their
other abstractions arent any better), their processing power is
growing at a rate of 151.2*10^6 keys/sec/day.  This would be the blue
line in the top graph.  Though I would otherwise compute a better
growth curve, I'll just take this somewhat off constant so as to leave
little for your two brain cells to argue.

   Key "acceleration" = Ka = 1750 k/s/s
   Key check rate     = Kr = 1750*t k/s
   Keys checked       = Kc = (1750*(t^2))/2 k

Let us assume that this project was begun 01JAN1998, again based on
that top graph and for simplicity's sake.  Let us also assume that
today is 31JUL2001.

   day  = 60*60*24                                = 86400
   year = day*365.25                              = 31557600.0
   ttd  = ((3*year)+((31+28+31+30+31+30+31)*day)) = 112989600.0 s

So how much of the keyspace have we searched so far?

   Kc(ttd)    = (1750*(ttd^2))/2 = 11.171*10^18 k
   Kc(ttd)/Ks = .605571          ~= 60.6%

We're already past the midpoint.  So barring any stupidities in the
software engineering (which shouldn't be too readily dismissed) and
continuing at present rates of growth, the key will be found by:

   Kc = 2^64  = (1750*(t^2))/2
    t = sqrt((2*(2^64))/1750)    ~= 145.2*10^6s -> 07AUG2002

It's becoming more and more likely to find the thing, i.e. your odds
are now at about 1:7.276*10^18 and approaching 1:1 as the pool of keys
remaining to be searched shrinks.

You seem to think your odds are 1:17000.  I shouldn't have to tell you
that you're a dolt.  Do your odds in the state lottery change
depending on the number of fellow participants?  The only thing in
variance here is the number of "tickets" that you "buy."

Rather than get hung up on that, though, let's move on and put
together your PC with average wattages[3][4]:

   Motherboard      - 25 W        Floppy           -  5   W
   CPU              - 30 W        CDR/W            - 17.5 W      
   RAM              - 10 W        DVD              - 17.5 W
   Video            - 25 W        IDE HD           - 10   W
   Sound            - 10 W        IDE HD           - 10   W
   NIC              -  5 W        Misc             -  5   W
   Serial/Parl/Misc - 10 W        Total ===========> 180W

Since it's likely that your floppy and CDs won't be spinning much,
I'll put it to 160W.  This is probably low.  We'll also assume that
you manage to turn off your monitor for the time you're not using the
system.  Demonstrating the intellectual prowess that you have, this is
probably also a poor assumption, but we'll go with it.

According to the DOE[5], the national average electric rate in 1998
was US$0.087 / KWH.  Let us presume that you've been caught, and will
continue to be caught in this 'distributed.net, from 01JAN1998 through
to 07AUG2002.  We'll also say that the rate is constant. Let's see how
much you'd have spent and will spend on power:

   t = ((4*year)+((31+28+31+30+31+30+31+7)*day))/3600 = 40320h
   P = (W*h)*($/W*h) = (160*40320)*(.087/1000) =======> $561.25

Hrm.  Not an insignificant amount of money.  About US$10.00 per month
over the course of the whole key search.  For no guarantee of a
return, monetary or otherwise.

If you want to look at the money angle alone, think of what you could
have earned in the market in 1998/1999.. or even a money market or
savings account.. or even buying a couple US$50.00 EE bonds every 5
months.

As far as the non-tangibles, what have you accomplished?  You've
voluntarily searched futilely for a needle you knew damn well was in
the haystack all along, under the false pretense that you'd be
celebrated for this "accomplishment."

Now apologise to all the people whose time you've wasted, then go sit
in the corner.

[1] http://www.distributed.net/rc5/index.html
[2] http://n0cgi.distributed.net/statistics/rc5-64/index.html
[3] http://pcpowercooling.com/maxpc/index_cases.htm
[4] Averages of averages and personal experience used where appropriate.
[5] http://www.eia.doe.gov/cneaf/electricity/epav1/epav1ta15.html

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