Patents by Inventor Hideaki Negawa

Hideaki Negawa 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).

  • Multicast communication system
    Patent number: 7055030
    Abstract: The present invention provides a multicast communication system having a multicast server and a plurality of clients belonging to a multicast group. The multicast server transmits data encrypted by using a first encryption key to the clients by multicasting, and transmits the result of encrypting the first encryption key by using a second encryption key by unicasting to a client subscribed to a data distribution service, among the plurality of clients. The client subscribed to the data distribution service receives the encrypted data and the result. The client decrypts the result to obtain the first encryption key and decrypts the encrypted data using the first encryption key.
    Type: Grant
    Filed: December 17, 2001
    Date of Patent: May 30, 2006
    Assignee: Fujitsu limited
    Inventor: Hideaki Negawa
  • Multicast communication system
    Publication number: 20030046539
    Abstract: The present invention provides a multicast communication system having a multicast server and a plurality of clients belonging to a multicast group. The multicast server transmits data encrypted by using a first encryption key to the clients by multicasting, and transmits the result of encrypting the first encryption key by using a second encryption key by unicasting to a client subscribed to a data distribution service, among the plurality of clients. The client subscribed to the data distribution service receives the encrypted data and the result. The client decrypts the result to obtain the first encryption key and decrypts the encrypted data using the first encryption key.
    Type: Application
    Filed: December 17, 2001
    Publication date: March 6, 2003
    Inventor: Hideaki Negawa