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Author

Yoshitomo Osawa

Other affiliations: Panasonic
Bio: Yoshitomo Osawa is an academic researcher from Sony Broadcast & Professional Research Laboratories. The author has contributed to research in topics: Key (cryptography) & Encryption. The author has an hindex of 25, co-authored 126 publications receiving 2572 citations. Previous affiliations of Yoshitomo Osawa include Panasonic.


Papers
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Journal ArticleDOI
TL;DR: This work uses simulation to compare different design choices in the Continuous Media File System, CMFS, and addresses several interrelated design issues; real-time semantics fo sessions, disk layout, an acceptance test for new sessions, and disk scheduling policy.
Abstract: The Continuous Media File System, CMFS, supports real-time storage and retrieval of continuous media data (digital audio and video) on disk. CMFS clients read or write files in “sessions,” each with a guaranteed minimum data rate. Multiple sessions, perhaps with different rates, and non-real-time access can proceed concurrently. CMFS addresses several interrelated design issues; real-time semantics fo sessions, disk layout, an acceptance test for new sessions, and disk scheduling policy. We use simulation to compare different design choices.

330 citations

Patent
04 Apr 2001
TL;DR: In this article, a block key to encrypt block data is generated using an ATS (arrival time stamp) appended to each of TS (transport stream) packets included in a transport stream correspondingly to the arrival time of the TS packet.
Abstract: A block key to encrypt block data is generated using an ATS (arrival time stamp) appended to each of TS (transport stream) packets included in a transport stream correspondingly to the arrival time of the TS packet. The ATS is a random data depending upon an arrival time, and so a block-unique key can be generated, which enhances the protection against data cryptanalysis. A block key is generated from a combination of an ATS with a key unique to a device, recording medium or the like such as a master key, disc-unique key, title-unique key or the like. Since an ATS is used to generate a block key, any area for storage of an encryption key for each block may not be provided in a recording medium.

154 citations

Patent
21 Dec 2001
TL;DR: In this article, the EKB has a structure in which a device constituting a tree leaf holds a leaf key and a limited node key, and a specific effective key block (EKB) is generated and distributed to a group specified by a specific node.
Abstract: A content key, an authentication key, program data along with an effective key block (EKB) are transmitted by an encryption key structure of a tree structure. The EKB has a structure in which a device constituting a tree leaf holds a leaf key and a limited node key. A specific effective key block (EKB) is generated and distributed to a group specified by a specific node, thus limiting an updateable device. A device not belonging to a group cannot be decoded, ensuring the distribution security of the key and so forth. Keys or data is distributed by an encryption key structure of tree structure, thereby providing an information processing system and method capable of efficiently and safely distributing data.

136 citations

Patent
05 Sep 2001
TL;DR: In this paper, a tree-structure key-distribution system for content encryption and decryption is proposed. But the system requires a special reading method for the secret information, which cannot be analyzed and which can be read only by a special reader.
Abstract: An information recording/playback device stores beforehand, on a recording medium, secret information in which a writing/reading method thereof cannot be analyzed and which can be read only by a special reading method. The secret information is applied to a key for content encryption or decryption when performing recording or playback of contents on the recording medium, such as music data and image data. The secret information is, for example, a stamper ID. By using the stamper ID as secret information, and a master key and a media key which are distributed in a tree-structure key-distribution system, a content-cryptosystem key is generated. Accordingly, each content is allowed to be used in only an appropriate device in which the special reading method for the secret information can be executed and to which the key is distributed by the tree-structure key-distribution system.

135 citations

Patent
19 Oct 1998
TL;DR: In this paper, a method and system for transferring information using an encryption mode indicator (EMI) is presented, in which data (e.g., representing an audio/visual work) can be transmitted from a source device to a sink device (receiving station) in a number of secure modes.
Abstract: A method and system for transferring information using an encryption mode indicator (EMI). The present invention provides several secure information communication modes in which data (e.g., representing an audio/visual work) can be transmitted from a source device to a sink device (receiving station) in a number of secure modes. In one secure mode, EMI mode A, the information of the transmission is not allowed to be copied as a whole work; this is the highest level of copy protection. In second secure mode, EMI mode B, the information of the transmission is allowed to be copied once and once only by the sink device. In a third transmission mode, no encryption is used and free copying is availabe. Depending on which secure mode is selected between mode A and mode B, a different encryption process is used by the source device to encrypt the transmission. Further, depending on which secure mode is selected between mode A and mode B, a different decryption process is used by the sink device to decrypt the transmission. The present invention is particularly useful for transmissions between a source device and a bit stream recorder which does not have the capability to extract certain encryption information from a packet header. By using different encryption processes for each transmission mode, an unauthorized device placed between the source and the sink devices that alters the EMI code will be unable to thereafter render or record the audio/visual work because the decryption process selected will differ from the encryption process used.

115 citations


Cited by
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Patent
30 Sep 2010
TL;DR: In this article, the authors proposed a secure content distribution method for a configurable general-purpose electronic commercial transaction/distribution control system, which includes a process for encapsulating digital information in one or more digital containers, a process of encrypting at least a portion of digital information, a protocol for associating at least partially secure control information for managing interactions with encrypted digital information and/or digital container, and a process that delivering one or multiple digital containers to a digital information user.
Abstract: PROBLEM TO BE SOLVED: To solve the problem, wherein it is impossible for an electronic content information provider to provide commercially secure and effective method, for a configurable general-purpose electronic commercial transaction/distribution control system. SOLUTION: In this system, having at least one protected processing environment for safely controlling at least one portion of decoding of digital information, a secure content distribution method comprises a process for encapsulating digital information in one or more digital containers; a process for encrypting at least a portion of digital information; a process for associating at least partially secure control information for managing interactions with encrypted digital information and/or digital container; a process for delivering one or more digital containers to a digital information user; and a process for using a protected processing environment, for safely controlling at least a portion of the decoding of the digital information. COPYRIGHT: (C)2006,JPO&NCIPI

7,643 citations

Patent
21 Dec 1998
TL;DR: In this article, the data is divided into segments and each segment is distributed randomly on one of several storage units, independent of the storage units on which other segments of the media data are stored.
Abstract: Multiple applications request data from multiple storage units over a computer network. The data is divided into segments and each segment is distributed randomly on one of several storage units, independent of the storage units on which other segments of the media data are stored. At least one additional copy of each segment also is distributed randomly over the storage units, such that each segment is stored on at least two storage units. This random distribution of multiple copies of segments of data improves both scalability and reliability. When an application requests a selected segment of data, the request is processed by the storage unit with the shortest queue of requests. Random fluctuations in the load applied by multiple applications on multiple storage units are balanced nearly equally over all of the storage units. This combination of techniques results in a system which can transfer multiple, independent high-bandwidth streams of data in a scalable manner in both directions between multiple applications and multiple storage units.

1,427 citations

Patent
14 May 2002
TL;DR: In this article, the data is divided into segments and each segment is distributed randomly on one of several storage units, independent of the storage units on which other segments of the media data are stored.
Abstract: Multiple applications request data from multiple storage units over a computer network. The data is divided into segments and each segment is distributed randomly on one of several storage units, independent of the storage units on which other segments of the media data are stored. Redundancy information corresponding to each segment also is distributed randomly over the storage units. The redundancy information for a segment may be a copy of the segment, such that each segment is stored on at least two storage units. The redundancy information also may be based on two or more segments. This random distribution of segments of data and corresponding redundancy information improves both scalability and reliability. When a storage unit fails, its load is distributed evenly over to remaining storage units and its lost data may be recovered because of the redundancy information. When an application requests a selected segment of data, the request may be processed by the storage unit with the shortest queue of requests. Random fluctuations in the load applied by multiple applications on multiple storage units are balanced nearly equally over all of the storage units. Small data files also may be stored on storage units that combine small files into larger segments of data using a log structured file system. This combination of techniques results in a system which can transfer both multiple, independent high-bandwidth streams of data and small data files in a scalable manner in both directions between multiple applications and multiple storage units.

1,195 citations

Patent
06 Nov 1998
TL;DR: In this article, a matching and classification utility system comprising a kind of Commerce Utility System is used to perform the matching, narrowcasting, classifying and/or selecting process, non-limiting examples of which include software objects.
Abstract: Rights management information is used at least in part in a matching, narrowcasting, classifying and/or selecting process. A matching and classification utility system comprising a kind of Commerce Utility System is used to perform the matching, narrowcasting, classifying and/or selecting. The matching and classification utility system may match, narrowcast, classify and/or select people and/or things, non-limiting examples of which include software objects. The Matching and Classification Utility system may use any pre-existing classification schemes, including at least some rights management information and/or other qualitative and/or parameter data indicating and/or defining classes, classification systems, class hierarchies, category schemes, class assignments, category assignments, and/or class membership. The Matching and Classification Utility may also use at least some rights management information together with any artificial intelligence, expert system, statistical, computational, manual, or any other means to define new classes, class hierarchies, classification systems, category schemes, and/or assign persons, things, and/or groups of persons and/or things to at least one class.

1,109 citations

Patent
03 Jan 1992
TL;DR: In this paper, a system of distributing video and audio information employs digital signal processing to achieve high rates of data compression, and the compressed and encoded audio and video information is sent over standard telephone, cable or satellite broadcast channels to a receiver specified by a subscriber of the service, preferably in less than real time, for later playback and optional recording on standard audio and/or video tape.
Abstract: A system of distributing video and/or audio information employs digital signal processing to achieve high rates of data compression. The compressed and encoded audio and/or video information is sent over standard telephone, cable or satellite broadcast channels to a receiver specified by a subscriber of the service, preferably in less than real time, for later playback and optional recording on standard audio and/or video tape.

1,032 citations