From: cbbrowne@csi.uottawa.ca (Christopher Browne)
Subject: Re: DES (Was: Re: 800MHz
Organization: Dept. of Computer Science, University of Ottawa
Date: Sat, 9 Jan 93 16:30:11 GMT

In article <1444.204.uupcb@ssr.com> jani.patokallio%acc1bbs@ssr.com (Jani Patokallio)  writes:
>In message <23.2B4A0D74@purplet.demon.co.uk> Owen Lewis <Owen.Lewis
>purplet.demon.co.uk> said:
>->  Another "likelihood theory":
>-> 
>-> What first world government permits the use of DES for the protection
>-> of classified material? Does the US government? I believe not.

Gripe #1:
The US is not part of the "first world".

The ordering is:

"Old World"  i.e. - Europe
"New World"  i.e. - the Americas, and generally NORTH America
"Third World" which refers to "the rest", generally dealing with
poorer/newer countries in some combination of Africa, Asia, and
sometimes South America.

North America is most certainly NOT in the "first world".

>->  And while we are discussing theories, I believe James Bamforth, the NSA 
>->  watcher, went on record some time ago with a claim that the cost to the US 
>->  taxpayer for breaking each DES ciphertext is $56. Can anyone supply the  
>->  assumptions from which he must have made this extrapolation?
>
>If the US has 250,000,000 people, the total cost is therefore 
>14,000,000,000 (14 trillion) dollars per ciphertext.  Even if around a
>third of those people do not pay taxes, I think Mr. Bamforth was exaggerating
>a little.

It is reasonable to believe that he was probably using a form of
hyperbole in which it is pretended that there is only one US taxpayer.
He most definitely did NOT say "the cost to each US taxpayer of
breaking each DES ciphertext is $56", which WOULD imply the $14T.

There's lots of griping about the "evil NSA," and lots of conspiracy
theories.  When someone "asks about assumptions," it is unkind (and a
waste of time) to pick holes in the question without at least TRYING
to answer what was asked.

If that $56 figure is faintly accurate, then I expect that the NSA
must have some rather high-speed hardware, probably specialized to
DES, that costs quite a bit less than anyone expected.  I would have
expected a somewhat higher bill.

I can give some basic "blanks" to fill in:

a) Number of messages processed: _____________

b) Mean Size of messages processed:   _____________  (may be important)

A * B = "total ciphertext"

c) Cost of electricity and staffing, per hour, for the NSA "DES
Breaker" computer:                  ____________

d) Average time to decrypt 1K of message on the "DES Breaker":
______________

Actually, one can probably get that $56 just out of figures b), c) and
d).

$56 = (b) * (c) / (d)

I'm ignoring capital costs, in this analysis, but I'd suspect that so
does the NSA.  Governments don't tend to consider "capital costs" to
be REAL costs, for a variety of reasons.

And if anyone wishes to publicise the values b), c) and d), that's
THEIR choice.  Those three numbers are probably considered QUITE
secret.

-- 
Christopher Browne                |     PGP 2.0 key available
cbbrowne@csi.uottawa.ca           |======================================
University of Ottawa              | Genius may have its limitations, but
Master of System Science Program  | stupidity is not thus handicapped.
Newsgroups: sci.crypt