John Nash's letters to the NSA (1955) [pdf]

https://www.nsa.gov/public_info/_files/nash_letters/nash_letters1.pdf

by jonbaer • 11 years ago

238 47 11 years ago

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• 11 years ago

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...

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.

throwawayaway2• 11 years ago

now that you mention it, the red threat of the 1950s and the civil rights movement are quite similar to the dangers posed by the American populace since 911.

readme4• 11 years ago

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.

madaxe_again2• 11 years ago

Who is this "the enemy" of which you speak? "Filthy Commies"? "Ragheads"? The Hun?

Come on, if you're going to go all nationalist on us do it wholeheartedly.

madaxe_again2• 11 years ago

Wait, you run a company (Aerospike) making a DB engine. It had better be backdoored and automatically relaying data to intelligence services, or at least banned for export without spyware - if that isn't the case, you're not living by your own mantra, and I'd be curious as to why not?

rumdz• 11 years ago

A Markov model can be represented as a finite state machine where transitions are probability driven (suppose I'm in a state 'a' and I can transition to state 'b' or 'c' where the probability of transitioning from 'a'->'b' is 30% and 'a'->'c' is 70%). The diagram on page 14 definitely looks like some sort of finite state machine but I don't know which classification it falls under. It doesn't switch states randomly so it's not a Markov chain.

shiro• 11 years ago

It's deterministic. Basically it's a state machine and the state transition table itself is the key, iiuc.

A few years ago I implemented it with software: http://blog.practical-scheme.net/gauche/20120715-nash-cipher...

plg• 11 years ago

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)

actualdc12• 11 years ago

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.

wfunction2• 11 years ago

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

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

callum85• 11 years ago

I can't find anything online supporting this.

amateurpolymath• 11 years ago

University of Virginia does this as well:

"Out of respect for the founder of the University who did not have a Ph.D., University faculty are referred to as Mr. or Mrs. instead of Doctor, even if they have a Ph.D. Students and faculty historically addressed each other in this manner. Medical doctors are the exception to the rule and they should be referred to as Doctor."

http://www.virginia.edu/deanofstudents/studenttraditions.htm...

hayd• 11 years ago

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

This seems a bit harsh!

kpatterson• 11 years ago

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.

xnull2guest2• 11 years ago

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.

kristopolous2• 11 years ago

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...). He's an Alan Turing in the field. Also see here (http://econtheory.org/) for some good sunday afternoon reading.

xnull2guest2• 11 years ago

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. :)

gwern• 11 years ago

Back when these were declassified, I prepared a transcript and annotated parts of it: 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.)

JabavuAdams• 11 years ago

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

pacifist• 11 years ago

This is why I always read the comments first.

fabulist• 11 years ago

The NSA publishes a lot of useful literature, such as guides for hardening network equipment or RHEL servers.

kanan• 11 years ago

Thanks for sharing such a great information..Its really nice and informative. http://www.joinfita.com/django-python-training-institutes-in...

mmuelly• 11 years ago

And I sent John Nash a letter recently: http://www.reddit.com/r/news/comments/376qv4/john_nash_taugh...

John Nash's letters to the NSA (1955) [pdf]

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