John Forbes Nash, Jr. Letters, National Security Agency

Document Title: John Forbes Nash, Jr. Letters, National Security Agency Release Date: 2015-02-24 The Black Vault Entry: https://www.theblackvault.com/documentarchive/john-forbes-nash-jr-letters-national-security-agency/ Canonical PDF: https://documents.theblackvault.com/documents/nsa/nash_letters1.pdf The National Security Agency released a collection of letters exchanged between the agency and mathematician John Forbes Nash, Jr. in the 1950s. These letters are notable for their discussion of cryptography and Nash's proposed enciphering-deciphering machine. The documents were released in response to a Freedom of Information Act request and are available on The Black Vault website. The letters were declassified in 2015. Please Note: These FOLLOWING historical documents are PDF images of formerly classified carbon paper and letters that have been declassified. Due to the age and poor quality of some of the PDF images, a screen reader may not be able to process the images into word documents. In accordance with Sections 504 and 508 of the Rehabilitation Act of 1973, as amended, individuals may request that the government provide auxiliary aids, ALTERNATE FORMATS, or services to ensure effective communication of the substance of the documents. For such requests, please contact the Public Affairs Office at 301-688-6524. MASSACHUSETTS INSTITUTE OF TECHNOLOGY CAMBRIDGE 39, MASS. DEPARTMENT OF MATHEMATICS MASSACHUSETTS INSTITUTE OF TECHNOLOGY CAMBRIDGE 39, MASS. DEPARTMENT OF MATHEMATICS } f.\4c ~~ v\s £t{ (. \?)1tR \wG - -~ / ir • John Nash Department of Mathematics Massachusetts Institute of Technology Cambridge 39, Massachusetts Dear Mr. Nash: I~ Serial: " "> Your recent letter, received " January 1955, is noted. 531 5 JAN 1955 Technicans at this Agency recall a very interesting discussion with you which took place approximately four years ago, and will welcome the opportunity to examine your ideas on the subject of cryptography. A check within this Agency has, unfortunately, disclosed no information on your machine. A description of the principles involved will be appreciated. cc: *'* .. 4 AG Cis COMSEC (3) 412 Sincerely , Eo M. Gibson Lt. Col., AGe Assistant Adj. Gen. M/R: In Jan 1955, Mr. Nash offered general remarks on cryptography and requested evaluation of descriptive material which he had forwarded through Rand Corp. NSA Ser 236, 12 Jan 55 informed Mr. Nash that the material had not arrived. Mr. Nash in letter rec'd 18 Jan 55 states the material was sent to NSA and to a Navy Communication Center in Wash. late last spring. A check of Agency records and discussions with various individuals (RID mathematicians and persons who might have had contact with Rand Corp.) within the Agency has uncovered nothing concerning the system. This correspondence requests a description of the machine. In 1950 Mr. Nash submitted material, in interview, which was evaluated by NSA as not suitable. Serial: _ _ 2 3 6 1 2 JAN 1~5" • John a.sh Department of Mathematics Massachusetts Institute of Technology Cambridge 39, Massachusetts Dear Mr. Nash: Reference is made to your recent letter concerning enciphering processes .. The general principles have been noted in interest. It will be considered, fully, and particularly in connection with your enciphering machine. The description of your machine has not yet been received from the Rand Corporation. As soon as these are received, the machine will be studied to determine whether it is of interest to the Government. The presentation for appraisal of your idea for safeguarding communications security is very much appreciated. cc : cis COMSEC (3) 412 Sincerely, E.M. Gibson Lt. Col., AGe Assistant Adj. Gen. M/R: In Jan 55 Mr. Nash offered general remarks on cryptography and requested evaluation of descriptive material which he had forwarded through Rand Corp. The material was not received from Rand Corp. Dr. Campaigne received a letter from Mr. Nash inclosing a copy of the letter (5 Apr 54) from Rand which transmitted this material to NSA. This material was found in R/D files. In the meantime Mr. Nash sent a handwritten description of his enciphering-deciphering machine. Mr. Nash proposes a permuting cipher-text auto-key principle which has many of the desirable features of a good auto-key system; but it affords only limited security, and requires a comparatively large amount of equipment. The principle would not be used alone in its present form and suitable modification or extension is considered unlikely, unless it could be used in conjunction with other good auto-key principles. This correspondence informs Mr. Nash that his system does not meet necessary security requirements; and expresses pleasure at the thought of an opportunity to discuss Mr. Nash's ideas on cryptography again. Such a discussion took place in 1950 when Mr. Nash submitted material, in interview, which was evaluated by NSA as unsuitable. An interesting pamphlet on Non-Cooperative Games, written by Mr. Nash was also sent to this Agency by the author for our information Dr. Campaigne has been informed that the reply has been written and is not interested in further coordination. This is what the public record looks like at its most ordinary. storyflo.com.