Patents by Inventor Ryuji Ishiguro

Ryuji Ishiguro 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).

  • Patent number: 7505599
    Abstract: An enabling key block (EKB) used in an encrypted key distributing tree structure is generated by forming a simplified 2-branch or multi-branch type tree with a terminal node or leaf which is capable of decrypting on the basis of a key corresponding to a node or a leaf of the Simplified tree. Further, the EKB includes a tag for indicating a position of an encrypted key in the tree. The tag not only discriminates position but also stores data for judging the presence of encrypted key data within the EKB. As such, a considerable reduction in data quantity is realized, and the decrypting process in a device is also simplified.
    Type: Grant
    Filed: April 4, 2001
    Date of Patent: March 17, 2009
    Assignee: Sony Corporation
    Inventors: Ryuji Ishiguro, Yoshitomo Osawa, Tateo Oishi, Tomoyuki Asano, Atsushi Mitsuzawa
  • Patent number: 7503073
    Abstract: The present invention relates to an information managing apparatus and method, a recording medium, and a program in which unauthorized use of content can be prevented. A ripping module 91 of a client 1 retrieves the content recorded on a CD 81. In the client 1, a content ID for identifying the content and a unique ID unique to the client 1 are generated, and these IDs are added to the content retrieved by the ripping module 91. A usage right containing the usage conditions of the content, etc., is generated and saved. The usage right includes information indicating that an apparatus (client) having the same ID to the unique ID added to the content is only allowed to play back the content. The present invention is applicable to an information processing apparatus such as a personal computer.
    Type: Grant
    Filed: April 10, 2003
    Date of Patent: March 10, 2009
    Assignee: Sony Corporation
    Inventors: Yoji Kawamoto, Ryuji Ishiguro, Yuichi Ezura, Motohiko Nagano
  • Patent number: 7487549
    Abstract: The present invention relates to an information processing apparatus, an information processing method, a recording medium, and a program for importing and exporting a content with information missing controlled. A CPU extracts a sound track contained in the content in step S301, and converts a format of the extracted sound track into a format compatible with a memory stick in step S302. The CPU generates a predetermined file from data contained in the content and excluding the sound track in step S304. In step S306, the CPU attaches reference information of the sound track to the file. In step S307, the CPU controls the writing of the sound track in the converted format and the file to the memory stick. The present invention is applied to clients of a DRM system.
    Type: Grant
    Filed: April 10, 2003
    Date of Patent: February 3, 2009
    Assignee: Sony Corporation
    Inventors: Yoji Kawamoto, Ryuji Ishiguro, Yuichi Ezura, Motohiko Nagano
  • Publication number: 20090010430
    Abstract: The present invention is directed to a streaming system for encrypting compression-encoded image data to distribute it via network of a predetermined transport protocol, and a streaming server used in this system transmits, to a client terminal, on the RTP packet basis, stream data encrypted so that encryption is performed every encryption block size from the leading portion of each GOP without encrypting the last data having less than encryption block size. In this instance, portions of prior and/or posterior stream data are stored into an extended area of RTP header so that size of stream data transmitted every RTP packet is integral multiple of encryption block size. Further, size information of added prior additional data and/or posterior additional data are also stored into the extended area. This streaming server suppresses increase in size by encryption to have ability to support both real time production and down-load reproduction without replacement of encryption.
    Type: Application
    Filed: April 24, 2008
    Publication date: January 8, 2009
    Inventors: Keiko Tada, Ryuji Ishiguro, Motomasa Futagami
  • Publication number: 20080289050
    Abstract: To provide a copyright protection storage medium in which copyright protected contents are recorded by an information recording apparatus connected to a content server providing copyright protected contents and a license server handling licenses concerning recording/playback of the copyright protected contents through a network, in which the copyright protected contents are written by a simple copy-and-paste when the information recording apparatus is possessed by a prescribed user, and the copyright protected contents are written by combining a domain model which assures playback in the apparatus and a media-bind model when the information recording apparatus is possessed by another user.
    Type: Application
    Filed: June 27, 2007
    Publication date: November 20, 2008
    Inventors: Yoji Kawamoto, Norifumi Goto, Ryuji Ishiguro
  • Patent number: 7443984
    Abstract: A content key, an authentication key, and a program data etc. are transmitted with an enabling key block (EKB) in an encrypted key constitution of a tree structure. The EKB has a constitution in which a device as a leaf of the tree holds a leaf key and a limited node key, and a specific enabling key block (EKB) is generated and distributed to a group specified by a specific node to limit devices that can be renewed. As the devices that do not belong to the group cannot perform decryption, the security for distributing keys etc. can be secured. Thus, distribution of various kinds of keys or data is executed in an encryption key constitution of a tree structure to realize an information processing system and method enabling to distribute data efficiently and safely.
    Type: Grant
    Filed: April 2, 2001
    Date of Patent: October 28, 2008
    Assignee: Sony Corporation
    Inventors: Ryuji Ishiguro, Yoshitomo Osawa, Tateo Oishi, Tomoyuki Asano, Atsushi Mitsuzawa
  • Patent number: 7437768
    Abstract: The CPU 11 of the personal computer 1 controls the CPU 32 of the adaptor 26 made of a semiconductor ID to compute a hash value of a content-managing music data base recorded in the HDD 21 and store it into the nonvolatile memory 34. When playing back a content recorded in the HDD 21, the CPU 11 computes the hash value of the music data base recorded in the HDD 21, compares it with hash values stored cumulatively in the nonvolatile memory 34, and controls the playback of the content from the HDD 21 based on the result of the comparison.
    Type: Grant
    Filed: October 19, 2005
    Date of Patent: October 14, 2008
    Assignee: Sony Corporation
    Inventors: Itaru Kawakami, Ryuji Ishiguro, Mitsuru Tanabe, Yuichi Ezura
  • Patent number: 7426639
    Abstract: This invention relates to an information processing apparatus for permitting so-called grouping without recourse to group keys. A content server retains in advance certificates of devices subject to grouping. Each certificate contains a public key of the corresponding device. When providing a content, the content server authenticates the certificates of the grouped devices for which the content is destined (step S281), encrypts a content key by use of public keys of the authenticated certificates (step S283), and transmits the content key thus encrypted to each of the devices making up the group (step S284) together with the content. The inventive apparatus is applied to devices that provide contents.
    Type: Grant
    Filed: March 27, 2002
    Date of Patent: September 16, 2008
    Assignee: Sony Corporation
    Inventor: Ryuji Ishiguro
  • Patent number: 7405731
    Abstract: An information processing system and method are disclosed in which information processing is performed in a highly efficient manner using an enabling key block (EKB) on the basis of a tree structure including category subtrees. A key tree is formed so as to include a plurality of subtrees serving as category trees categorized in accordance with categories and managed by category entities. An EKB includes data produced by selecting a path in a tree and encrypting a higher-level key in the selected path using a lower-level key in the selected path. The resultant EKB is provided to a device. Distribution of EKB's is managed on the basis of an EKB type definition list representing the correspondence between an EKB type identifier and one or more identification data identifying one or more category trees that can process an EKB of an EKB type specified by the EKB type identifier.
    Type: Grant
    Filed: May 19, 2005
    Date of Patent: July 29, 2008
    Assignee: Sony Corporation
    Inventors: Tomoyuki Asano, Yoshitomo Osawa, Tateo Oishi, Ryuji Ishiguro, Ryuta Taki
  • Publication number: 20080092243
    Abstract: The present invention relates to an information managing apparatus and method, a recording medium, and a program in which unauthorized use of content can be prevented. A ripping module 91 of a client 1 retrieves the content recorded on a CD 81. In the client 1, a content ID for identifying the content and a unique ID unique to the client 1 are generated, and these IDs are added to the content retrieved by the ripping module 91. A usage right containing the usage conditions of the content, etc., is generated and saved. The usage right includes information indicating that an apparatus (client) having the same ID to the unique ID added to the content is only allowed to play back the content. The present invention is applicable to an information processing apparatus such as a personal computer.
    Type: Application
    Filed: October 26, 2007
    Publication date: April 17, 2008
    Inventors: Yoji Kawamoto, Ryuji Ishiguro, Yuichi Ezura, Motohiko Nagano
  • Patent number: 7346170
    Abstract: An information processing system and method are disclosed in which information processing is performed using an enabling key block (EKB) in association with a tree structure including category subtrees. A key tree is produced, which include subtrees that are grouped in accordance with categories and are managed by category entities. The EKB includes data produced by selecting a path in the key tree and encrypting a higher-level key in the selected path using a lower-level key in the selected path. The EKB is then provided to a device. A requester, which requests production of the EKB, may produce a root key or may request a key distribution center (KDC) to produce a root key. If the (KDC) produces the EKB, it may also request a category entity to produce a sub-EKB.
    Type: Grant
    Filed: December 21, 2001
    Date of Patent: March 18, 2008
    Assignee: Sony Corporation
    Inventors: Tomoyuki Asano, Yoshitomo Osawa, Tateo Oishi, Ryuji Ishiguro, Ryuta Taki
  • Patent number: 7346169
    Abstract: An information processing device, information processing method and a recording medium are provided. Storage included in the information processing device is operable to store a node key and a leaf key, the leaf key being unique to the information processing device and the node key being unique to each node of a hierarchical network of nodes having a hierarchical tree structure. A decryption processor performs decryption processing to detect whether an encrypted decryption key for decrypting encrypted data is stored in at least one of on the information processing device or on a recording medium. When the encrypted decryption key is detected, the decryption processor is operable to calculate the decryption key by decrypting the encrypted decryption key. However, when the encrypted decryption key is not detected, the decryption processor is operable to calculate the decryption key by decrypting a key block using one of the one or more node keys stored in the storage and the leaf key stored in the storage.
    Type: Grant
    Filed: June 21, 2001
    Date of Patent: March 18, 2008
    Assignee: Sony Corporation
    Inventors: Tomoyuki Asano, Yoshitomo Osawa, Ryuji Ishiguro, Atsushi Mitsuzawa, Tateo Oishi
  • Patent number: 7337320
    Abstract: The present invention is directed to a streaming system for encrypting encrypted data such as music and image, etc. to perform stream distribution thereof. Client terminals (30) used in this system structure leaves of the hierarchical tree structure, and hold a key set consisting of a route key, node keys and the own leaf key on a path of this tree structure, whereby SDP file is transmitted from a stream server (20). In the SDP file, there is stored encrypted information consisting of EKB including data encrypted by selection key that only specific client terminal holds and encrypted contents key data in which contents key has been encrypted. Only specific client terminal having selection key in key set (selected client terminal) decodes contents key from selection key to decode encrypted contents data caused to undergo stream distribution into contents data to perform real time reproduction thereof.
    Type: Grant
    Filed: January 28, 2003
    Date of Patent: February 26, 2008
    Assignee: Sony Corporation
    Inventors: Keiko Tada, Ryuji Ishiguro, Motomasa Futagami
  • Patent number: 7336791
    Abstract: Upon receipt of a service data request from a client, a license server offering a key to decrypt a content transmits a user information request to the client. On receiving the user information request, the client displays a message prompting its user to enter such user information as the user's personal information and accounting information. The user information thus entered is sent from the client to the license server. On receiving the user information, the license server assigns a leaf of a key-managed hierarchical tree structure to the client, generates a set of node keys as a device node key, sends to the client the device node key together with a leaf ID and a private key of the client in question, and records the user information in correspondence with the leaf ID.
    Type: Grant
    Filed: March 27, 2002
    Date of Patent: February 26, 2008
    Assignee: Sony Corporation
    Inventor: Ryuji Ishiguro
  • Patent number: 7325139
    Abstract: The present invention relates to an information processing apparatus and method and to a program for reliably preventing unauthorized use of content even in the case of a low-throughput content storage device. A CPU selects content to be stored on a content storage device. In step S202, the CPU verifies a first digital signature added to the content. A storage unit stores a usage right. In step S203, the CPU searches the storage unit for the usage right. In step S207, the CPU verifies a second digital signature added to the usage right. The CPU generates alteration detecting data on the basis of information included in the usage right. In step S208, when the content and the usage right are unaltered, the CPU outputs the usage right, the alteration detecting data, and the content to the content storage device. The present invention is applicable to clients in a DRM system.
    Type: Grant
    Filed: April 10, 2003
    Date of Patent: January 29, 2008
    Assignee: Sony Corporation
    Inventors: Ryuji Ishiguro, Keiko Tada, Motomasa Futagami
  • Publication number: 20080013723
    Abstract: The invention provides an enciphering apparatus and method, a deciphering apparatus and method and an information processing apparatus and method by which illegal copying can be prevented with certainty. Data enciphered by a 1394 interface of a DVD player is transmitted to a personal computer and a magneto-optical disk apparatus through a 1394 bus. In the magneto-optical disk apparatus with which a change to a function is open to a user, the received data is deciphered by a 1394 interface. In contrast, in the personal computer with which a change to a function is open to a user, the enciphered data is deciphered using a time variable key by a 1394 interface, and a result of the decipherment is further deciphered using a session key by an application section.
    Type: Application
    Filed: July 3, 2007
    Publication date: January 17, 2008
    Inventors: Ryuji Ishiguro, Yoshitomo Osawa, Yoshio Osakabe, Makoto Sato, Hisato Shima, Tomoyuki Asano
  • Publication number: 20070289025
    Abstract: A client receives encrypted content from content server. The header of the content includes license-identifying information for identifying a license required to utilize the content. The client requests a license server to transmit the license identified by the license-identifying information. When receiving the request for a license, the license server carries out a charging process before transmitting the license to the client. The client stores the license received from the license server. The stored license serves as a condition for encrypting and playing back the content. As a result, content can be distributed with a high degree of freedom and only an authorized user is capable of utilizing the content.
    Type: Application
    Filed: April 5, 2007
    Publication date: December 13, 2007
    Applicant: Sony Corporation
    Inventors: Koichi Tanaka, Itaru Kawakami, Yoshisuke Kuroda, Ryuji Ishiguro
  • Patent number: 7298842
    Abstract: The invention provides an enciphering apparatus and method, a deciphering apparatus and method and an information processing apparatus and method by which illegal copying can be prevented with certainty. Data enciphered by a 1394 interface of a DVD player is transmitted to a personal computer and a magneto-optical disk apparatus through a 1394 bus. In the magneto-optical disk apparatus with which a change to a function is not open to a user, the received data is deciphered by a 1394 interface. In contrast, in the personal computer with which a change to a function is open to a user, the enciphered data is deciphered using a time variable key by a 1394 interface, and a result of the decipherment is further deciphered using a session key by an application section.
    Type: Grant
    Filed: June 1, 2001
    Date of Patent: November 20, 2007
    Assignee: Sony Corporation
    Inventors: Ryuji Ishiguro, Yoshitomo Osawa, Yoshio Osakabe, Makoto Sato, Hisato Shima, Tomoyuki Asano
  • Publication number: 20070263875
    Abstract: An information processing system and method using an encryption key block sets sub-trees classified based on data processing ability of the devices (capability) in a key tree in which respective keys are corresponded to a root, nodes and leaves of a tree in which a plurality of devices are constituted as the leaves, generates a sub-enabling key block which is effective for an entity in a managing subject of each sub-tree (entity), and generates an enabling key block decodable only by the entities having common capability. Also, an information processing system and method using an encryption key block manages a partial tree of a key tree (sub-tree), generates a sub-enabling key block based only on a key set corresponding to nodes or leaves included in the sub-tree, and generates an enabling key block decodable only by selected entities by using the sub-enabling key block.
    Type: Application
    Filed: July 18, 2007
    Publication date: November 15, 2007
    Applicant: Sony Corporation
    Inventors: Yoshimichi Kitaya, Ryuji Ishiguro, Yoshitomo Osawa, Tomoyuki Asano
  • Patent number: 7296153
    Abstract: A cipher key is generated by first information shared in secrete between a data transmitting unit 10 and a data receiving unit 20, second information derived from duplication control information of transmit data and third information which is time change information shared between the data transmitting unit and the data receiving unit to cipher data by a CPU 12 by using the above-mentioned cipher key to transmit, from the data transmitting unit 10 to the data receiving unit 20, transmit data in which the duplication control information and the time change information are added to the ciphered data.
    Type: Grant
    Filed: April 22, 2005
    Date of Patent: November 13, 2007
    Assignee: Sony Corporation
    Inventors: Tomoyuki Asano, Yoshitomo Osawa, Teruyoshi Komuro, Ryuji Ishiguro