Patents by Inventor Sakae Chikara

Sakae Chikara 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).

  • Cryptographic system, cryptographic communication method, encryption apparatus, key generation apparatus, decryption apparatus, content server, program, and storage medium
    Patent number: 8995660
    Abstract: A cryptographic communication technology that is based on functional encryption and that can operate flexibly is provided. A conversion rule information pair is determined in advance, which has attribute conversion rule information prescribing a conversion rule for converting attribute designation information to attribute information used in a functional encryption algorithm and logical expression conversion rule information prescribing a conversion rule for converting logical expression designation information to logic information used in the functional encryption algorithm. One kind of conversion rule information included in the conversion rule information pair is used to obtain first attribute information or first logic information from input information. The first attribute information or the first logic information is used for encryption.
    Type: Grant
    Filed: July 22, 2011
    Date of Patent: March 31, 2015
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Tetsutaro Kobayashi, Kaku Takeuchi, Sakae Chikara
  • Cryptographic system, cryptographic communication method, encryption apparatus, key generation apparatus, decryption apparatus, content server, program, and storage medium
    Patent number: 8964982
    Abstract: A cryptographic communication technology that is based on predicate encryption and that can operate flexibly is provided. A conversion rule information pair is determined in advance, which has attribute conversion rule information prescribing a conversion rule for converting attribute designation information to attribute information used in a predicate encryption algorithm and predicate conversion rule information prescribing a conversion rule for converting predicate designation information to predicate information used in the predicate encryption algorithm. One kind of conversion rule information included in the conversion rule information pair is used to obtain first attribute information or first predicate information from input information. The first attribute information or the first predicate information is used for encryption.
    Type: Grant
    Filed: April 23, 2010
    Date of Patent: February 24, 2015
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Kaku Takeuchi, Tetsutaro Kobayashi, Sakae Chikara
  • CRYPTOGRAPHIC SYSTEM, CRYPTOGRAPHIC COMMUNICATION METHOD, ENCRYPTION APPARATUS, KEY GENERATION APPARATUS, DECRYPTION APPARATUS, CONTENT SERVER, PROGRAM, AND STORAGE MEDIUM
    Publication number: 20130114810
    Abstract: A cryptographic communication technology that is based on functional encryption and that can operate flexibly is provided. A conversion rule information pair is determined in advance, which has attribute conversion rule information prescribing a conversion rule for converting attribute designation information to attribute information used in a functional encryption algorithm and logical expression conversion rule information prescribing a conversion rule for converting logical expression designation information to logic information used in the functional encryption algorithm. One kind of conversion rule information included in the conversion rule information pair is used to obtain first attribute information or first logic information from input information. The first attribute information or the first logic information is used for encryption.
    Type: Application
    Filed: July 22, 2011
    Publication date: May 9, 2013
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Tetsutaro Kobayashi, Kaku Takeuchi, Sakae Chikara
  • CRYPTOGRAPHIC SYSTEM, CRYPTOGRAPHIC COMMUNICATION METHOD, ENCRYPTION APPARATUS, KEY GENERATION APPARATUS, DECRYPTION APPARATUS, CONTENT SERVER, PROGRAM, AND STORAGE MEDIUM
    Publication number: 20120027210
    Abstract: A cryptographic communication technology that is based on predicate encryption and that can operate flexibly is provided. A conversion rule information pair is determined in advance, which has attribute conversion rule information prescribing a conversion rule for converting attribute designation information to attribute information used in a predicate encryption algorithm and predicate conversion rule information prescribing a conversion rule for converting predicate designation information to predicate information used in the predicate encryption algorithm. One kind of conversion rule information included in the conversion rule information pair is used to obtain first attribute information or first predicate information from input information. The first attribute information or the first predicate information is used for encryption.
    Type: Application
    Filed: April 23, 2010
    Publication date: February 2, 2012
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORP.
    Inventors: Kaku Takeuchi, Tetsutaro Kobayashi, Sakae Chikara