Patents by Inventor William F. Friedman

William F. Friedman has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Cryptographs
    Patent number: 6130946
    Abstract: The cryptographic system automatically and continuously changes the cipher equivalents representing plaintext characters so as to prevent any periodicity in the relationship. The system has a series of juxtaposed, rotatable, connection changing mechanisms to provide a large number of alternative paths for the passage of an electric current corresponding to a message character. Further, the system has parts for the irregular and permutative displacements of the members of a set of circuit changing mechanisms to thwart cryptanalysis. The juxtaposed cipher commutators are controlled by cam wheels of different diameters.
    Type: Grant
    Filed: October 23, 1936
    Date of Patent: October 10, 2000
    Assignee: The United States of America as represented by the National Security Agency
    Inventor: William F. Friedman
  • Cryptographic system
    Patent number: 6097812
    Abstract: The crytographic system automatically and continuously changes the cipher equivalents representing plaintext characters so as to prevent any periodicity in the relationship. The system has a series of juxtaposed, rotatable, connection changing mechanisms to provide a large number of alternative paths for the passage of an electric current corresponding to a message character. Further, the system has parts for the irregular and permutative displacements of the members of a set of circuit changing mechanisms to thwart cryptanalysis.
    Type: Grant
    Filed: July 25, 1933
    Date of Patent: August 1, 2000
    Assignee: The United States of America as represented by the National Security Agency
    Inventor: William F. Friedman