Patents by Inventor Toshiyasu Muta

Toshiyasu Muta 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).

  • Method and apparatus for settlement of accounts by IC cards
    Patent number: 5502765
    Abstract: An IC card has a card information memory area wherein there are written a master public key nA, card secret keys pU and qU, a card public key nU, a card identification number IDU, and a first master digital signature SA1 for information including the card identification number. An IC card terminal has terminal information memory area wherein there are written a master public key nA, terminal secret keys pT and qT, a terminal public key nT, a terminal identification number IDT, and a second master digital signature SA2 for information including the terminal identification number IDT. When inserted into the IC card terminal, the IC card sends thereto the data nU, IDU, and SA1. The IC card terminal verifies the digital signature SA1 by the master public key nA and, if it is valid, transmits the data nT, IDT and SA2 to the IC card.
    Type: Grant
    Filed: October 31, 1994
    Date of Patent: March 26, 1996
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Ginya Ishiguro, Toshiyasu Muta, Kazutaka Sakita, Shoji Miyaguchi, Tatsuaki Okamoto, Atsushi Fujioka
  • Method and apparatus for settlement of accounts by IC cards
    Patent number: 5446796
    Abstract: An IC card has a card information memory area wherein there are written a master public key nA, card secret keys pU and qU, a card public key nU, a card identification number IDU, and a first master digital signature SA1 for information including the card identification number. An IC card terminal has terminal information memory area wherein there are written a master public key nA, terminal secret keys pT and qT, a terminal public key nT, a terminal identification number IDT, and a second master digital signature SA2 for information including the terminal identification number IDT. When inserted into the IC card terminal, the IC card sends thereto the data nU, IDU, and SA1. The IC card terminal verifies the digital signature SA1 by the master public key nA and, if it is valid, transmits the data nT, IDT and SA2 to the IC card.
    Type: Grant
    Filed: October 31, 1994
    Date of Patent: August 29, 1995
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Ginya Ishiguro, Toshiyasu Muta, Kazutaka Sakita, Shoji Miyaguchi, Tatsuaki Okamoto, Atsushi Fujioka
  • Method and apparatus for settlement of accounts by IC cards
    Patent number: 5396558
    Abstract: An IC card has a card information memory area wherein there are written a master public key nA, card secret keys pU and qU, a card public key nU, a card identification number IDU, and a first master digital signature SA1 for information including the card identification number. An IC card terminal has terminal information memory area wherein there are written a master public key nA, terminal secret keys pT and qT, a terminal public key nT, a terminal identification number IDT, and a second master digital signature SA2 for information including the terminal identification number IDT. When inserted into the IC card terminal, the IC card sends thereto the data nU, IDU, and SA1. The IC card terminal verifies the digital signature SA1 by the master public key nA and, if it is valid, transmits the data nT, IDT and SA2 to the IC card.
    Type: Grant
    Filed: September 13, 1993
    Date of Patent: March 7, 1995
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Ginya Ishiguro, Toshiyasu Muta, Kazutaka Sakita, Shoji Miyaguchi, Tatsuaki Okamoto, Atsushi Fujioka