4 ms·

John Nash's Letter to the NSA

296 points by ckuehne 15y ago

hsmyers 15y ago
Tough call---part of me says that they blew it off while the rest of me says they put the information to work (as best as they were able) In any event I doubt they got back to him...
- peterwwillis 15y ago
  The PDF record shows both parties replied to each other a couple times but the NSA thought his method didn't meet their security criteria. But they also could have shelved it for years until someone had a use for it, the same as Hedy Lamarr's frequency hopping patent. (Granted, they probably modified it slightly so they didn't have to give him any credit)
  - blake8086 15y ago
    This may be of some use to you: http://en.wikipedia.org/wiki/Hedy_Lamarr http://en.wikipedia.org/wiki/Hedy_Lamarr
  - VikingCoder 15y ago
    It's "Hedley"! (Sorry - mandatory "Blazing Saddles" joke.)
- DanBC 15y ago
  GCHQ didn't appear to make any use of Public Key crypto, even though Clifford Cocks created it. But maybe there's a bunch of documents that are still secret.
- ChuckMcM 15y ago
  Amusing anecdote, I was quite taken with the 'Java Ring' (which was a class ring type ring with a Dallas iButton on it) because it could be a 'secret decoder ring' with real crypto, except that all the crypto bits were disabled because they did not have permission from the NSA to turn them on. So I wrote an Enigma Machine simulator for it [1] which used BASE64 to encrypt (or decrypt) messages. And in the process of doing research for that article I discovered the patent for the 'rotor' used in enigma [2] which was filed in Oct 10th, 1944 but didn't issue until Oct 12th, 1976! Talk about your submarine patent! But the other interesting thing about 1976 is that the DES encryption standard was announced in November of that year. I don't doubt for a minute that Nash's work was influential on the thinking at least of the development of that standard. [1] http://www.javaworld.com/javaworld/jw-08-1998/jw-08-indepth.html http://www.javaworld.com/javaworld/jw-08-1998/jw-08-indepth.... [2] http://www.google.com/patents/US3984922 http://www.google.com/patents/US3984922
  - SimHacker 15y ago
    Oooh, enigma, submarine patent, U-110 so funny! http://instantrimshot.com/ http://instantrimshot.com/
- beambot 15y ago
  From a cursory read of the PDF [1], it would seem that Mr. Nash was describing a stream cipher [2]. [1] http://courses.csail.mit.edu/6.857/2012/files/H03-Cryptosystem-proposed-by-Nash.pdf http://courses.csail.mit.edu/6.857/2012/files/H03-Cryptosyst... [2] http://en.wikipedia.org/wiki/Stream_cipher http://en.wikipedia.org/wiki/Stream_cipher
- drostie 15y ago
  Well, they might have used the idea, but it's not really something easily tractable even for them. I have to admit, I'm reading Rivest's source code and I don't completely grok the encryption scheme yet, but it seems to me that it works like this. Here's the problem: you've got this very pretty conjecture which says "give me just 26 cards, there are about 2^88 permutations of them, and choosing one at random produces a much larger set of possibilities than we could guess in the forseeable future with brute-force techniques." He then provide a cipher which takes a shuffled deck and 26 spots in memory, and uses the red half and the black half to provide a random pathway for the bits through this network, since at each step there is an incoming bit which tells which way you shuffle. (And I gather that also some of the cards may basically be flipped upside down when storing the key, which means "flip the bit as you transmit it.") It's perfectly valid as an observation, and a nice conjecture, although I'm a little bit concerned in many ways about the design, since it still seems like it only has 2^26 state leaked pretty straightforwardly one bit at a time from two different locations. But maybe he's correct. Still there's something technologically missing. This is a very simple algorithm for modern computers with their array lookups, and I suppose the military had all the budget they needed to build large machines which can actually push around these bits, but that sort of mixing network would have been really difficult to implement mechanically. In a world where computers were too expensive to distribute to every ship's captain, I could see the NSA being much less interested in this sort of physically pushing bits around a complicated network via pathways that won't be known until run-time.
moonboots 15y ago
I can't help but think that the NSA would have taken the letter more seriously if had been typed. http://www.nsa.gov/public_info/_files/nash_letters/nash_letters1.pdf http://www.nsa.gov/public_info/_files/nash_letters/nash_lett...
- thebooktocome 15y ago
  Type math? In 1955? That would have required specialized equipment, possibly a secretary. Nash clearly believed that the contents were of national security interest.
  - moonboots 15y ago
    He should have invented TeX.
    - VikingCoder 15y ago
      I think he did. Unfortunately he also invented fonts that appear to be hand-drawn by a person suffering from schizophrenia. =(
      - vecter 15y ago
        I can't tell if you're kidding or not, but John Nash definitely did not invent TeX: http://en.wikipedia.org/wiki/TeX http://en.wikipedia.org/wiki/TeX.
      - SimHacker 15y ago
        Here's a font that appears to be hand-drawn by a person suffering from megalomania: http://www.fonts101.com/fonts/view/Uncategorized/34398/Dijkstra.aspx http://www.fonts101.com/fonts/view/Uncategorized/34398/Dijks...
  - DanBC 15y ago
    The diagram with the red and blue lines is particularly "interesting" for anyone not keeping up with the math. "I'm not a crank. Here's a diagram of my machine." {Blue and red line everywhere}.
ohashi 15y ago
I am pretty sure you can see them at the cryptography museum right next to the NSA. I went two weeks ago and Nash letter is right in the front.
thebigshane 15y ago
National Geographic recently had a "special" on "Inside the NSA: America's Cyber Secrets" where they mentioned and showed this letter. They said the NSA didn't end up doing anything with it but still wanted to classify it for 50+ years so that no one else could use the ideas within. My favorite parts of the episode were: - All of the Windows XP machines everyone was using - The flashing red lights on the ceiling in secure areas (familiar for those that have been in similar secure facilities) - The obnoxious re-enactments where real employees pretend to gather and discuss on-going developments. It was outright silly. The episode just aired in January and it looks like it isn't on their site yet, but there are related videos: http://www.nationalgeographic.com/search/?search=%22Inside+the+NSA%22 http://www.nationalgeographic.com/search/?search=%22Inside+t... EDIT: The NSA press release mentions it too. They say "featured" but they didn't spend more than 5 minutes out of the hour program. The Nash letters were also recently featured on the National Geographic [...]
- jberryman 15y ago
  Why the lights on the ceiling?
  - dsr_ 15y ago
    To announce that there are uncleared visitors in the room, so don't discuss anything confidential.
  - thebigshane 15y ago
    In secure facilities (particularly defense related) where secret information or networks are in use, visitors must be accompanied by an escort and announced before entering. Everyone has to stop any actual sensitive work, shut off their monitors to sensitive systems, and cover up sensitive documents on your desk. Then as long as the visitor is in a certain area of the building, red flashing lights (no siren/noise) must stay on to alert everyone else that an un-cleared visitor is currently in the area. This is why most "actual work" gets done in basements and extra-secure rooms where visitors rarely ever see, because the constant interruptions are devastating.
skrebbel 15y ago
I wonder what letters / blog posts / emails are written now that will make us look back in awe in 60 years.
- steve-howard 15y ago
  I wonder if such things still happen. In 1955, the world was a lot less interconnected, and there was a much more real sense of global tension such that you would want to keep secrets. Today I'm not sure an academic would be so quick to dash off a letter to someone who would keep their discoveries secret for half a century.

296 points by ckuehne 15y ago

Tough call---part of me says that they blew it off while the rest of me says they put the information to work (as best as they were able) In any event I doubt they got back to him...

peterwwillis 15y ago
The PDF record shows both parties replied to each other a couple times but the NSA thought his method didn't meet their security criteria. But they also could have shelved it for years until someone had a use for it, the same as Hedy Lamarr's frequency hopping patent. (Granted, they probably modified it slightly so they didn't have to give him any credit)
- blake8086 15y ago
  This may be of some use to you: http://en.wikipedia.org/wiki/Hedy_Lamarr http://en.wikipedia.org/wiki/Hedy_Lamarr
- VikingCoder 15y ago
  It's "Hedley"! (Sorry - mandatory "Blazing Saddles" joke.)
DanBC 15y ago
GCHQ didn't appear to make any use of Public Key crypto, even though Clifford Cocks created it. But maybe there's a bunch of documents that are still secret.
ChuckMcM 15y ago
Amusing anecdote, I was quite taken with the 'Java Ring' (which was a class ring type ring with a Dallas iButton on it) because it could be a 'secret decoder ring' with real crypto, except that all the crypto bits were disabled because they did not have permission from the NSA to turn them on. So I wrote an Enigma Machine simulator for it [1] which used BASE64 to encrypt (or decrypt) messages. And in the process of doing research for that article I discovered the patent for the 'rotor' used in enigma [2] which was filed in Oct 10th, 1944 but didn't issue until Oct 12th, 1976! Talk about your submarine patent! But the other interesting thing about 1976 is that the DES encryption standard was announced in November of that year. I don't doubt for a minute that Nash's work was influential on the thinking at least of the development of that standard. [1] http://www.javaworld.com/javaworld/jw-08-1998/jw-08-indepth.html http://www.javaworld.com/javaworld/jw-08-1998/jw-08-indepth.... [2] http://www.google.com/patents/US3984922 http://www.google.com/patents/US3984922
- SimHacker 15y ago
  Oooh, enigma, submarine patent, U-110 so funny! http://instantrimshot.com/ http://instantrimshot.com/
beambot 15y ago
From a cursory read of the PDF [1], it would seem that Mr. Nash was describing a stream cipher [2]. [1] http://courses.csail.mit.edu/6.857/2012/files/H03-Cryptosystem-proposed-by-Nash.pdf http://courses.csail.mit.edu/6.857/2012/files/H03-Cryptosyst... [2] http://en.wikipedia.org/wiki/Stream_cipher http://en.wikipedia.org/wiki/Stream_cipher
drostie 15y ago
Well, they might have used the idea, but it's not really something easily tractable even for them. I have to admit, I'm reading Rivest's source code and I don't completely grok the encryption scheme yet, but it seems to me that it works like this. Here's the problem: you've got this very pretty conjecture which says "give me just 26 cards, there are about 2^88 permutations of them, and choosing one at random produces a much larger set of possibilities than we could guess in the forseeable future with brute-force techniques." He then provide a cipher which takes a shuffled deck and 26 spots in memory, and uses the red half and the black half to provide a random pathway for the bits through this network, since at each step there is an incoming bit which tells which way you shuffle. (And I gather that also some of the cards may basically be flipped upside down when storing the key, which means "flip the bit as you transmit it.") It's perfectly valid as an observation, and a nice conjecture, although I'm a little bit concerned in many ways about the design, since it still seems like it only has 2^26 state leaked pretty straightforwardly one bit at a time from two different locations. But maybe he's correct. Still there's something technologically missing. This is a very simple algorithm for modern computers with their array lookups, and I suppose the military had all the budget they needed to build large machines which can actually push around these bits, but that sort of mixing network would have been really difficult to implement mechanically. In a world where computers were too expensive to distribute to every ship's captain, I could see the NSA being much less interested in this sort of physically pushing bits around a complicated network via pathways that won't be known until run-time.

moonboots 15y ago

I can't help but think that the NSA would have taken the letter more seriously if had been typed. http://www.nsa.gov/public_info/_files/nash_letters/nash_letters1.pdf http://www.nsa.gov/public_info/_files/nash_letters/nash_lett...

thebooktocome 15y ago
Type math? In 1955? That would have required specialized equipment, possibly a secretary. Nash clearly believed that the contents were of national security interest.
- moonboots 15y ago
  He should have invented TeX.
  - VikingCoder 15y ago
    I think he did. Unfortunately he also invented fonts that appear to be hand-drawn by a person suffering from schizophrenia. =(
    - vecter 15y ago
      I can't tell if you're kidding or not, but John Nash definitely did not invent TeX: http://en.wikipedia.org/wiki/TeX http://en.wikipedia.org/wiki/TeX.
    - SimHacker 15y ago
      Here's a font that appears to be hand-drawn by a person suffering from megalomania: http://www.fonts101.com/fonts/view/Uncategorized/34398/Dijkstra.aspx http://www.fonts101.com/fonts/view/Uncategorized/34398/Dijks...
- DanBC 15y ago
  The diagram with the red and blue lines is particularly "interesting" for anyone not keeping up with the math. "I'm not a crank. Here's a diagram of my machine." {Blue and red line everywhere}.

ohashi 15y ago

I am pretty sure you can see them at the cryptography museum right next to the NSA. I went two weeks ago and Nash letter is right in the front.

thebigshane 15y ago

National Geographic recently had a "special" on "Inside the NSA: America's Cyber Secrets" where they mentioned and showed this letter. They said the NSA didn't end up doing anything with it but still wanted to classify it for 50+ years so that no one else could use the ideas within. My favorite parts of the episode were: - All of the Windows XP machines everyone was using - The flashing red lights on the ceiling in secure areas (familiar for those that have been in similar secure facilities) - The obnoxious re-enactments where real employees pretend to gather and discuss on-going developments. It was outright silly. The episode just aired in January and it looks like it isn't on their site yet, but there are related videos: http://www.nationalgeographic.com/search/?search=%22Inside+the+NSA%22 http://www.nationalgeographic.com/search/?search=%22Inside+t... EDIT: The NSA press release mentions it too. They say "featured" but they didn't spend more than 5 minutes out of the hour program. The Nash letters were also recently featured on the National Geographic [...]

jberryman 15y ago
Why the lights on the ceiling?
- dsr_ 15y ago
  To announce that there are uncleared visitors in the room, so don't discuss anything confidential.
- thebigshane 15y ago
  In secure facilities (particularly defense related) where secret information or networks are in use, visitors must be accompanied by an escort and announced before entering. Everyone has to stop any actual sensitive work, shut off their monitors to sensitive systems, and cover up sensitive documents on your desk. Then as long as the visitor is in a certain area of the building, red flashing lights (no siren/noise) must stay on to alert everyone else that an un-cleared visitor is currently in the area. This is why most "actual work" gets done in basements and extra-secure rooms where visitors rarely ever see, because the constant interruptions are devastating.

skrebbel 15y ago

I wonder what letters / blog posts / emails are written now that will make us look back in awe in 60 years.

steve-howard 15y ago
I wonder if such things still happen. In 1955, the world was a lot less interconnected, and there was a much more real sense of global tension such that you would want to keep secrets. Today I'm not sure an academic would be so quick to dash off a letter to someone who would keep their discoveries secret for half a century.