
John Nash's letters to the NSA (1955) [pdf] - jonbaer
https://www.nsa.gov/public_info/_files/nash_letters/nash_letters1.pdf
======
gwern
Back when these were declassified, I prepared a transcript and annotated parts
of it: [http://gwern.net/docs/1955-nash](http://gwern.net/docs/1955-nash) Good
for those who don't want to go through the scanned PDF version but a HTML
version. (My version also has links to various discussions such as class
exercises in breaking his proposed system.)

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xnull2guest
This was in 1955!

There are comments here trying to contrast Nash's work to modern cryptography,
as though that's somehow fair. Nash never had access to anything remotely like
a personal computer and this is just after the age - and in fact still one -
where physical and mechanical devices were being used to perform encryption.

The better thing to do would be to compare (rather than contrast) his work.
Look at this letter. Nash essentially predicts trapdoor functions and the P/NP
gap... in a mere letter.

We were lucky to have Nash and his contributions. It's unfortunate that most
of his academic work is largely unknown and that pop science focuses
disproportionately on his work on equilibrium in symmetric games.

May he rest in peace.

~~~
kristopolous
In Economic Theory, the words "Nash Equilibrium" is said at least once an hour
in every lecture hall. It's a pretty obvious focus (see here:
[http://math.uchicago.edu/~shmuel/AAT-
readings/Econ%20segment...](http://math.uchicago.edu/~shmuel/AAT-
readings/Econ%20segment/On%20Nash%20Eq.pdf)). He's an Alan Turing in the
field. Also see here ([http://econtheory.org/](http://econtheory.org/)) for
some good sunday afternoon reading.

~~~
xnull2guest
Of course. There is no ill will toward or deemphasis of Nash Equilibria. :)

Merely, it's a shame that MORE of Nash's contributions haven't been as
popularly traded. This popular science emphasis at the opportunity cost of
others leads to the impression that this is all Nash has contributed. That's
all I was getting at. :)

~~~
kristopolous
Alright. But honestly, if I got my namesake on some kind of fundamental
theory, I'd be pretty ok with everything else being forgotten.

I can imagine the awkwardness of grad students presenting their work in a room
where he was present ... "and so-and-so forms a nash equilibrium ... (silence,
looking for approval from Johns face, sigh of relief from grad student when
professor does not shake head in dismay)"

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plg
Why do the generals refer to him as Mr. Nash? (and not Dr. Nash, or Prof.
Nash)?

It's not like the military is not used to being precise about titles (i.e.
ranks)

~~~
actualdc1
I could be wrong, but I believe that Princeton PhD's go by "mister" instead of
"doctor."

Princeton considers itself a unique institution in this way. They do not
accept transfer students, they do not have any professional degree programs,
etc.

~~~
wfunction
> I believe that Princeton PhD's go by "mister" instead of "doctor."

Would you have a reference for this? This is really interesting.

~~~
dcurtis
From
[http://www.princeton.edu/communications/services/editorial/r...](http://www.princeton.edu/communications/services/editorial/resources/style-
guide/) :

> “Use the title Dr. only when referring to a medical doctor.”

~~~
javajosh
Apropos of nothing, these rules seem mechanical enough to be codified as
software. Has anyone done so?

P.S. A more specific link would be the "Titles" subsection,
[http://www.princeton.edu/communications/services/editorial/r...](http://www.princeton.edu/communications/services/editorial/resources/style-
guide/#comp00004e9d39280000000b18628d)

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niels_olson
The diagram on page 14 (page 3 of the machine description) vaguely resembles a
Markov model, which I could imagine would be useful for cryptanalysis, but I
don't see how such a system would be reasonable for encryption or decryption
if you have the keys. Am I misunderstanding the machine?

~~~
bbulkow
The NSA's response said about the same thing, once you get to the end --- not
interesting, not reasonable for encryption and decryption.

Interesting, I think, the statement that Nash's machine requires
"comparatively" too much hardware. This implies the NSA did have auto-keying
systems at the time that had higher security, and lower hardware burden.

Remember, in '55 we didn't have single-chip CPUs, we barely had practical
transistors, we didn't have planar process circuits (invented in about '60
according to the computer history museum).

[http://www.computerhistory.org/revolution/digital-
logic/12/3...](http://www.computerhistory.org/revolution/digital-logic/12/329)

Nash believed in helping the US keep its secrets safe, and exposing the
secrets of the enemy. One thing to remember when you look at Snowden's papers
exposing not just domestica activities but foreign activities.

~~~
readme
Today's generation is strongly detached from the military, I think that is
why.

If everyone had a close family member or friend serving they would care more
about the security of military operations.

Like it or not we have enemies still and need to maintain this secrecy to
protect our country.

~~~
MichaelGG
My brother is in the US Army (and so was my cousin). I don't believe that
Snowden-like reveals put him in any more specific danger - AFAIK, he's at much
higher risk from "insurgent" activity, which the US's actions have created
without any help from leaks.

Nor is using the word "serving" instead of "working" beneficial to how people
think about it. It's a job, he enjoys it, he's fairly well compensated (good
credit, benefits, etc.) The military offers all sorts of bonuses and
recruiting tactics to hire people, like other companies. You're not forced
into the military, and when he joined, the various divisions were actually
quite picky and it took a while to find a properly compensating match, just
like other employers. (Though in my cousin's case, after suffering severe
damage on base, they had no trouble discharging her to a rather miserable
life, hey just like other corporations.)

~~~
mpyne
> I don't believe that Snowden-like reveals put him in any more specific
> danger

That's true only in the same way that sending half-rations to your soldiers on
the front line instead of full rations doesn't put them in "more specific"
danger.

Or in a civilian context, refusing to wear seat belts doesn't put people in
any "more specific" danger, nor does smoking cigarettes. Yet we understand
that statistically speaking across the entire population in question, that it
is possible to reduce the risk of harm by taking specific actions that have
general impact.

In the case of the military, it's always a double-ended question. There is the
risk added or reduced for your force in particular, but also the risk added or
reduced for the adversary forces.

E.g. you put "insurgent" in scare-quotes when mentioning that they actually
pose a danger to your family in the military, but without seeming to realize
that many of the NSA programs Snowden leaked are directly aimed at those very
same insurgents putting your family at risk. Even if we take it as true that
the U.S. managed to unilaterally create insurgencies (which is by no means the
case), that is not the fault of U.S. servicemembers like your family any more
so than any other non-U.S. politician.

To loop back to my point about managing general risk, the things that Snowden
leaks had disastrous real effects, including second- and third- order effects.
Beyond improving the security posture of U.S. insurgent adversaries and terror
networks (terror networks that strike against U.S. allies in addition to the
U.S. itself, I might add), Snowden's leaks also had the effect of weakening
the national intelligence agencies of important U.S. allies, and reducing
Western nations to infighting even as they needed to be able to present a
united front due to geopolitical changes. It's hard to make statements about
past "what-ifs" (though that has never stopped Snowden's supporters from
chicken-littling about future what-ifs...), but certainly the joint U.S./E.U.
reaction to Russia's invasion of Crimea would be more meaningful without
Snowden's actions a year earlier.

But just because these risks (for the U.S. and for the possible adversaries or
the U.S.) can't be quantified or laid out in short and simple flowcharts
doesn't mean that those risks don't exist.

~~~
kansface
|the things that Snowden leaks had disastrous real effects,

I agree, this is undoubtedly true. I also firmly believe Snowden is a hero.
Any highly illegal or immoral activity of the US government (or any government
for that matter) could be hidden under the same argument. We live in a
democracy. It is impossible to change the government if we don't know what our
government is doing in secret. Put succinctly, you advocate we shoot the
messenger. Have you consider that it is the government who has placed the
troops in harm's way by undertaking such outrageous, immoral, and illegal
actions as opposed to the guy who merely told us about it.

~~~
readme
Have you considered the idea that Snowden is working for the Russians?

He is in Russia, you know. That's a bit... odd, yeah?

What better post-cold war tactic than to weaken the capabilities of an
organization that spies on Russia than by decreasing its public approval.

~~~
MichaelGG
What other strong countries are there, that wouldn't give into US threats,
that'd offer him a place to live worth living in? China? Just curious how the
case of a true whistleblower would look different from a secret agent.

~~~
mpyne
China is actually a great example. They are today stronger than Russia, they
are a target themselves of NSA spying, and like Russia they are resentful of
the "U.S. led international order". So much as China thumbs its nose at the
U.S. by pushing back against U.S. presence in the Western Pacific, they'd have
every reason to host Snowden as a cause célèbre. That would certainly have
involved less air travel for Snowden as well!

But Wikileaks told Snowden to go to Russia, and in any event China told
Snowden to leave. Why would China do that? Because Snowden wasn't their
asset...

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hayd
"Dr. Campaigne has been informed that the reply has been written and is not
interested in further coordination."

This seems a bit harsh!

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JabavuAdams
Jesus Fuck! Did I just download a PDF from the NSA!? Derp.

~~~
pacifist
This is why I always read the comments first.

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mmuelly
And I sent John Nash a letter recently:
[http://www.reddit.com/r/news/comments/376qv4/john_nash_taugh...](http://www.reddit.com/r/news/comments/376qv4/john_nash_taught_me_the_connection_between/)

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kanan
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kpatterson
A true genius of his time to us public folk, yet still behind NSA standards
for security. I'm sure we will be seeing transformer-esque AI with Tesla
batteries and gravity guns in the next XX (or X?) years.

