Patents by Inventor Takamasa Isohara

Takamasa Isohara 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).

  • Publication number: 20190068381
    Abstract: A communication system is provided, including a plurality of terminal devices and a root certification authority. Each of the plurality of terminal devices includes a certification authority key generation unit, a certification authority public key certificate acquisition unit that acquires a certification authority public key certificate, a certification authority key storage unit, a transmission unit, and a verification unit that verifies the certification authority public key certificate with a root certification authority public key certificate, and verifies a user in a case where the verification succeeds. The root certification authority includes a root certification authority key storage unit, a communication unit, and a certification authority public key certificate generation unit that generates the certification authority public key certificate by encrypting the certification authority public key with the root certification authority secret key.
    Type: Application
    Filed: February 21, 2017
    Publication date: February 28, 2019
    Applicant: KDDI CORPORATION
    Inventors: Keisuke TAKEMORI, Takamasa ISOHARA, Teruaki HONMA
  • Publication number: 20180314813
    Abstract: A communication device includes: a first subscriber identification unit that stores first subscriber identification unit identification information associated with user identification information; and a communication unit that communicates with another communication device, the other communication device including a second subscriber identification unit that stores second subscriber identification unit identification information associated with user identification information.
    Type: Application
    Filed: October 19, 2016
    Publication date: November 1, 2018
    Applicant: KDDI CORPORATION
    Inventors: Keisuke TAKEMORI, Takamasa ISOHARA, Yoshiyuki SHIBATA, Kei KATOU, Teruaki HONMA
  • Patent number: 7673334
    Abstract: A communication system and a security assurance device are proposed, which are capable of assuring that a target party for communication is implementing security countermeasures. A server 3 transmits information 104 necessary for AC issuance to a security assurance authority 2. The security assurance authority 2 verifies the security of the server 3 during communication based upon this information necessary for AC issuance 104. And, when the security of the server 3 during communication is confirmed, the security assurance authority 2 issues an AC 105 which proves the security of the server 3 during communication, and transmits it to the server 3. Upon receipt of this AC 105, the server 3 transmits the AC 105 to a client 4, according to a connection request from the client 4. And, upon receipt of this AC 105, the client 4 verifies the security during communication of the server 3, based upon the AC 105.
    Type: Grant
    Filed: August 26, 2005
    Date of Patent: March 2, 2010
    Assignees: KDDI Corporation, KEIO University
    Inventors: Keisuke Takemori, Yutaka Miyake, Toshiaki Tanaka, Takamasa Isohara, Iwao Sasase
  • Publication number: 20060048228
    Abstract: A communication system and a security assurance device are proposed, which are capable of assuring that a target party for communication is implementing security countermeasures. A server 3 transmits information 104 necessary for AC issuance to a security assurance authority 2. The security assurance authority 2 verifies the security of the server 3 during communication based upon this information necessary for AC issuance 104. And, when the security of the server 3 during communication is confirmed, the security assurance authority 2 issues an AC 105 which proves the security of the server 3 during communication, and transmits it to the server 3. Upon receipt of this AC 105, the server 3 transmits the AC 105 to a client 4, according to a connection request from the client 4. And, upon receipt of this AC 105, the client 4 verifies the security during communication of the server 3, based upon the AC 105.
    Type: Application
    Filed: August 26, 2005
    Publication date: March 2, 2006
    Inventors: Keisuke Takemori, Yutaka Miyake, Toshiaki Tanaka, Takamasa Isohara, Iwao Sasase