Patents by Inventor Akihiro Kasahara
Akihiro Kasahara 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).
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Publication number: 20150312043Abstract: To reduce a load on a user terminal imposed when verifying signature data and at the same time reduce a load on a server, a signature key matrix KM includes a plurality of signature keys Ki-j arranged in a matrix structure of m rows and n columns, and is stored in a signature key matrix database 21. A correspondence relationship between a signature key set CK which is an aggregate of any signature keys selected from the n columns respectively and a user terminal 30 is stored in a correspondence relationship information database 22. A signature data generating unit 24 generates signature data having a matrix structure by encrypting a content digest D generated based on content data C by n number of signature keys included in the signature key matrix KM.Type: ApplicationFiled: September 11, 2014Publication date: October 29, 2015Inventors: Hiroshi Suu, Akira Miura, Akihiro Kasahara, Shinichi Matsukawa
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Publication number: 20150261941Abstract: A recording device configured to store content data in an encrypted manner, the recording device comprises a memory unit which stores various data, and a controller which controls the memory unit. The controller possesses a controller key and unique identification information, and is configured to generate a controller-unique key unique for each controller in accordance with the controller key and the identification information. The memory unit stores an MKB generated by encrypting a medium key with a device key set that is a collection of a plurality of device keys, an encrypted device key set generated by encrypting the device key set with the controller-unique key, and a device-key-set index which uniquely identifies the device key set.Type: ApplicationFiled: June 2, 2015Publication date: September 17, 2015Applicant: Kabushiki Kaisha ToshibaInventors: Shinichi MATSUKAWA, Taku Kato, Akihiro Kasahara, Hiroshi Suu, Atsushi Kondo, Jun Sato, Akira Miura, Hiroyuki Sakamoto
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Publication number: 20150234752Abstract: According to one embodiment, a memory chip, which is connected to a controller that controls reading and writing of data in response to a request from an external device, includes: a memory including a special area that is a predetermined data storage area; a key storage unit that stores therein a second key that corresponds to a first key used by the external device to convert the data; a converting unit that receives, from the controller, data to be written into the special area and generates converted data by converting the data to be written using the second key; and a writing unit that writes the converted data into the special area.Type: ApplicationFiled: April 30, 2015Publication date: August 20, 2015Applicant: Kabushiki Kaisha ToshibaInventors: Toru KAMBAYASHI, Akihiro KASAHARA, Shinichi MATSUKAWA, Hiroyuki SAKAMOTO, Taku KATO, Hiroshi SUKEGAWA, Yoshihiko HIROSE, Atsushi SHIMBO, Koichi FUJISAKI
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Patent number: 9083512Abstract: A recording device configured to store content data in an encrypted manner, the recording device comprises a memory unit which stores various data, and a controller which controls the memory unit. The controller possesses a controller key and unique identification information, and is configured to generate a controller-unique key unique for each controller in accordance with the controller key and the identification information. The memory unit stores an MKB generated by encrypting a medium key with a device key set that is a collection of a plurality of device keys, an encrypted device key set generated by encrypting the device key set with the controller-unique key, and a device-key-set index which uniquely identifies the device key set.Type: GrantFiled: October 3, 2013Date of Patent: July 14, 2015Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Shinichi Matsukawa, Taku Kato, Akihiro Kasahara, Hiroshi Suu, Atsushi Kondo, Jun Sato, Akira Miura, Hiroyuki Sakamoto
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Patent number: 9053062Abstract: According to one embodiment, a memory chip, which is connected to a controller that controls reading and writing of data in response to a request from an external device, includes: a memory including a special area that is a predetermined data storage area; a key storage unit that stores therein a second key that corresponds to a first key used by the external device to convert the data; a converting unit that receives, from the controller, data to be written into the special area and generates converted data by converting the data to be written using the second key; and a writing unit that writes the converted data into the special area.Type: GrantFiled: June 13, 2014Date of Patent: June 9, 2015Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Toru Kambayashi, Akihiro Kasahara, Shinichi Matsukawa, Hiroyuki Sakamoto, Taku Kato, Hiroshi Sukegawa, Yoshihiko Hirose, Atsushi Shimbo, Koichi Fujisaki
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Patent number: 8929547Abstract: According to one embodiment, a content data reproduction system includes a host device which uses content data, and a storage device configured such that content data, which is obtained by decrypting encrypted content data that is created by encrypting the content data by content key data, is made usable in the host device. The host device includes a device ID which is uniquely allocated to each of host devices. The storage device includes a memory and a controller configured to control the memory.Type: GrantFiled: March 19, 2012Date of Patent: January 6, 2015Assignee: Kabushiki Kaisha ToshibaInventors: Shinichi Matsukawa, Akira Miura, Hiroshi Suu, Hiroyuki Sakamoto, Akihiro Kasahara
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Patent number: 8887153Abstract: To reduce a load on a user terminal imposed when verifying signature data and at the same time reduce a load on a server, a signature key matrix KM includes a plurality of signature keys Ki-j arranged in a matrix structure of m rows and n columns, and is stored in a signature key matrix database 21. A correspondence relationship between a signature key set CK which is an aggregate of any signature keys selected from the n columns respectively and a user terminal 30 is stored in a correspondence relationship information database 22. A signature data generating unit 24 generates signature data having a matrix structure by encrypting a content digest D generated based on content data C by n number of signature keys included in the signature key matrix KM.Type: GrantFiled: November 25, 2009Date of Patent: November 11, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Hiroshi Suu, Akira Miura, Akihiro Kasahara, Shinichi Matsukawa
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Publication number: 20140298043Abstract: According to one embodiment, a memory chip, which is connected to a controller that controls reading and writing of data in response to a request from an external device, includes: a memory including a special area that is a predetermined data storage area; a key storage unit that stores therein a second key that corresponds to a first key used by the external device to convert the data; a converting unit that receives, from the controller, data to be written into the special area and generates converted data by converting the data to be written using the second key; and a writing unit that writes the converted data into the special area.Type: ApplicationFiled: June 13, 2014Publication date: October 2, 2014Applicant: Kabushiki Kaisha ToshibaInventors: Toro Kambayashi, Akihiro Kasahara, Shinichi Matsukawa, Hiroyuki Sakamoto, Taku Kato, Hiroshi Sukegawa, Yoshihiko Hirose, Atsushi Shimbo, Koichi Fujisaki
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Publication number: 20140289529Abstract: To exclude any unauthorized device from a system and thereby prevent illegal use of content data, a memory card 10 stores a service key Ksrv for encrypting content key data Kc in a hidden area 14. The memory card 10 stores answer data AC to be obtained when question data Q is fed to a host function F possessed by an authorized host device 20, with encryption applied to the answer data AC by the service key Ksrv. When the question data Q is provided to the host device 20, answer data AH is obtained based on the question data Q and the host function F. A comparison unit 122 judges match or mismatch of the answer data AH and the answer data AC. When they match, the memory card 10 decrypts the content key data Kc encrypted by the service key Ksrv and sends it to the host device 20.Type: ApplicationFiled: May 12, 2014Publication date: September 25, 2014Inventors: Shinichi Matsukawa, Akihiro Kasahara, Hiroshi Suu, Akira Miura
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Publication number: 20140250308Abstract: To exclude any unauthorized device from a system and thereby prevent illegal use of content data, a memory card 10 stores a service key Ksrv for encrypting content key data Kc in a hidden area 14. The memory card 10 stores answer data AC to be obtained when question data Q is fed to a host function F possessed by an authorized host device 20, with encryption applied to the answer data AC by the service key Ksrv. When the question data Q is provided to the host device 20, answer data AH is obtained based on the question data Q and the host function F. A comparison unit 122 judges match or mismatch of the answer data AH and the answer data AC. When they match, the memory card 10 decrypts the content key data Kc encrypted by the service key Ksrv and sends it to the host device 20.Type: ApplicationFiled: May 12, 2014Publication date: September 4, 2014Applicant: Kabushiki Kaisha ToshibaInventors: Shinichi Matsukawa, Akihiro Kasahara, Hiroshi Suu, Akira Miura
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Patent number: 8818268Abstract: In this content data delivery method, content data is transmitted from a content server to a first semiconductor device through a network. Then, the content data, content ID identifying the content data, and route data showing a route through which the content data is transmitted are transmitted from the first semiconductor device to a second semiconductor device using close-proximity wireless communication. Thereafter, the content ID and the route data are transmitted from the second semiconductor device to the content server. In addition, based on the route data, a reward corresponding to the content ID is calculated for the first semiconductor device, and the reward is provided to the first semiconductor device.Type: GrantFiled: March 21, 2012Date of Patent: August 26, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Tsukasa Matoba, Shinichi Matsukawa, Akihiro Kasahara, Hiroyuki Sakamoto
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Patent number: 8799682Abstract: To exclude any unauthorized device from a system and thereby prevent illegal use of content data, a memory card 10 stores a service key Ksrv for encrypting content key data Kc in a hidden area 14. The memory card 10 stores answer data ACto be obtained when question data Q is fed to a host function F possessed by an authorized host device 20, with encryption applied to the answer data AC by the service key Ksrv. When the question data Q is provided to the host device 20, answer data AH is obtained based on the question data Q and the host function F. A comparison unit 122 judges match or mismatch of the answer data AH and the answer data AC. When they match, the memory card 10 decrypts the content key data Kc encrypted by the service key Ksrv and sends it to the host device 20.Type: GrantFiled: April 16, 2009Date of Patent: August 5, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Shinichi Matsukawa, Akihiro Kasahara, Hiroshi Suu, Akira Miura
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Patent number: 8788907Abstract: According to one embodiment, a memory chip, which is connected to a controller that controls reading and writing of data in response to a request from an external device, includes: a memory including a special area that is a predetermined data storage area; a key storage unit that stores therein a second key that corresponds to a first key used by the external device to convert the data; a converting unit that receives, from the controller, data to be written into the special area and generates converted data by converting the data to be written using the second key; and a writing unit that writes the converted data into the special area.Type: GrantFiled: June 24, 2013Date of Patent: July 22, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Toru Kambayashi, Akihiro Kasahara, Shinichi Matsukawa, Hiroyuki Sakamoto, Taku Kato, Hiroshi Sukegawa, Yoshihiko Hirose, Atsushi Shimbo, Koichi Fujisaki
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Patent number: 8750519Abstract: This data protection system encrypts and stores data in a memory card, using a double encryption key scheme for encrypting the data with a data key and further encrypting the data key with a user key. This system provides data to a particular host device from the memory card and limits provision of the data to other host devices. The host device includes DPS program that governs control of writing data to, and reading data from the memory card. The memory card includes a first non-volatile memory and a memory controller that controls the first non-volatile memory. DPSA program is implemented in the memory controller that manages ID information for identifying a user capable of decrypting the encrypted data with the user key.Type: GrantFiled: May 27, 2009Date of Patent: June 10, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Hiroshi Suu, Akihiro Kasahara, Akira Miura
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Patent number: 8731202Abstract: Spread of a forged storage medium is prevented suppressing an authentic storage medium's damage and trouble of a owner to the minimum. When there is an update request of user key data, the update history of the user key data concerning the shown above-mentioned medium identifier IDm is referred to. When judged that the update of the user key data concerning the shown medium identifier IDm not being performed within a predetermined period, the update of user key data is performed. The request of a update is refused when judged that the update of the user key data concerning the shown medium identifier IDm being performed within a predetermined period.Type: GrantFiled: February 9, 2012Date of Patent: May 20, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Akihiro Kasahara, Akira Miura, Hiroshi Suu
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Patent number: 8689356Abstract: A handheld device is configured to be connectable to a storage media that holds a unique media identifier and holds a content key data used to decrypt an encrypted content data. A content data delivery system is provided that is configured to be able to deliver various data to the handheld device and to make a content data available to the handheld device. The system includes a member-registration information database that holds member-registration information including a data pair of a handheld-device identifier related to the relevant handheld device and the relevant media identifier. The media identifier held by the storage media is verified with the member-registration information database.Type: GrantFiled: August 15, 2012Date of Patent: April 1, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Akihiro Kasahara, Akira Miura, Hiroshi Suu
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Publication number: 20140040634Abstract: A recording device configured to store content data in an encrypted manner, the recording device comprises a memory unit which stores various data, and a controller which controls the memory unit. The controller possesses a controller key and unique identification information, and is configured to generate a controller-unique key unique for each controller in accordance with the controller key and the identification information. The memory unit stores an MKB generated by encrypting a medium key with a device key set that is a collection of a plurality of device keys, an encrypted device key set generated by encrypting the device key set with the controller-unique key, and a device-key-set index which uniquely identifies the device key set.Type: ApplicationFiled: October 3, 2013Publication date: February 6, 2014Applicant: Kabushiki Kaisha ToshibaInventors: Shinichi Matsukawa, Taku Kato, Akihiro Kasahara, Hiroshi Suu, Atsushi Kondo, Jun Sato, Akira Miura, Hiroyuki Sakamoto
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Patent number: 8578177Abstract: A recording device configured to store content data in an encrypted manner, the recording device comprises a memory unit which stores various data, and a controller which controls the memory unit. The controller possesses a controller key and unique identification information, and is configured to generate a controller-unique key unique for each controller in accordance with the controller key and the identification information. The memory unit stores an MKB generated by encrypting a medium key with a device key set that is a collection of a plurality of device keys, an encrypted device key set generated by encrypting the device key set with the controller-unique key, and a device-key-set index which uniquely identifies the device key set.Type: GrantFiled: March 4, 2010Date of Patent: November 5, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Shinichi Matsukawa, Taku Kato, Akihiro Kasahara, Hiroshi Suu, Atsushi Kondo, Jun Sato, Akira Miura, Hiroyuki Sakamoto
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Publication number: 20130290738Abstract: According to one embodiment, a memory chip, which is connected to a controller that controls reading and writing of data in response to a request from an external device, includes: a memory including a special area that is a predetermined data storage area; a key storage unit that stores therein a second key that corresponds to a first key used by the external device to convert the data; a converting unit that receives, from the controller, data to be written into the special area and generates converted data by converting the data to be written using the second key; and a writing unit that writes the converted data into the special area.Type: ApplicationFiled: June 24, 2013Publication date: October 31, 2013Inventors: Toru KAMBAYASHI, Akihiro Kasahara, Shinichi Matsukawa, Hiroyuki Sakamoto, Taku Kato, Hiroshi Sukegawa, Yoshihiko Hirose, Atsushi Shimbo, Koichi Fujisaki
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Patent number: 8473810Abstract: According to one embodiment, a memory chip, which is connected to a controller that controls reading and writing of data in response to a request from an external device, includes: a memory including a special area that is a predetermined data storage area; a key storage unit that stores therein a second key that corresponds to a first key used by the external device to convert the data; a converting unit that receives, from the controller, data to be written into the special area and generates converted data by converting the data to be written using the second key; and a writing unit that writes the converted data into the special area.Type: GrantFiled: September 15, 2010Date of Patent: June 25, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Toru Kambayashi, Akihiro Kasahara, Shinichi Matsukawa, Hiroyuki Sakamoto, Taku Kato, Hiroshi Sukegawa, Yoshihiko Hirose, Atsushi Shimbo, Koichi Fujisaki