Patents by Inventor Philip R. Zimmermann

Philip R. Zimmermann 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).

  • Patent number: 7730309
    Abstract: A method and system for a secure telephone protocol are disclosed, which can be implemented using current Voice over IP (VoIP) protocols, Session Initiation Protocol (SIP, as specified in the Request for Comment (RFC) 3261 from the Internet Engineering Task Force (IETF)), Real Time Transport Protocol (RTP, as specified in RFC 3550), and Secure RTP (SRTP, as specified in RFC 3711). The secure telephone protocol can include a shared secret value that is cached and then re-used later to authenticate a long series of session keys to be used for numerous separate secure phone calls over a long period of time, thereby providing cryptographic key continuity without the need for voice authentication. In an embodiment, the secure telephone protocol can utilize the Diffie-Hellman key exchange during call setup, and AES for encrypting the voice stream.
    Type: Grant
    Filed: July 27, 2006
    Date of Patent: June 1, 2010
    Inventor: Philip R. Zimmermann
  • Patent number: 5471190
    Abstract: A control communication network system adapted for distributed control and communication between various home electrical appliances in a manner that eliminates the need for a central controller and eliminates or greatly simplifies the manual assignment of addresses, control relationships or other network resources. The system utilizes a novel and useful process of "hailing" for addresses or resources by newly introduced network devices combined with a process by which declaratory statements are used to convey identification or resource availability information to potential controlling devices. The present invention comprises an intelligent lightswitch which can be dynamically "taught" to control or to be controlled by any other similar lightswitch in a given house without special wiring or user intervention other than the toggling of a simple "teach/learn" switch associated with each lightswitch.
    Type: Grant
    Filed: April 15, 1992
    Date of Patent: November 28, 1995
    Assignee: Timothy D. Schoechle
    Inventor: Philip R. Zimmermann