NSA advanced knowledge

Responding to msg by rsalz@osf.org (Rich Salz) on Wed, 24 Jan  
7:34 PM

>Is there any indication that the NSA knew about 
>public-key before  it entered the open literature?


   Fred B. Wrixon writes in "Codes and Ciphers," under the
   "Public Key" entry:

      ... This Hellman-Diffie proposal was apparently
      anticipated by a similar version developed by the
      National Security Agency (NSA) a decade earlier.
      (p. 164)

   No citation or elaboration is given for this claim.

   Wrixon's book is a simply written compendium:

      Codes and Ciphers: An A to Z of Covert Communication,
      from the Clay Tablet to the Microdot.
      Fred B. Wrixon
      Prentice Hall, 1992. Paper $18.00
      ISBN 0-13-277047-4