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Patent Issued for Server, Content Providing Apparatus, Content Receiving Apparatus, Content Providing Method, Content Receiving Method, and Program

February 11, 2014



By a News Reporter-Staff News Editor at Information Technology Newsweekly -- A patent by the inventor Muraoka, Kazuhiko (Kanagawa, JP), filed on July 30, 2004, was published online on January 28, 2014, according to news reporting originating from Alexandria, Virginia, by VerticalNews correspondents.

Patent number 8640178 is assigned to Sony Corporation (Tokyo, JP).

The following quote was obtained by the news editors from the background information supplied by the inventors: "This invention relates to a server, a content providing apparatus and a content receiving apparatus that are suitable for application to the case of distributing content data such as video programs through a network such as the Internet, a content providing method and a content receiving method applied to these apparatuses, and a program for executing these methods.

"Conventionally, in a streaming service to distribute a relatively large volume of content data such as video programs through the Internet, one server for providing contents is installed or servers for providing contents are installed at one place, and many clients are connected to the server in a centralized manner.

"Specifically, for example, as shown in FIG. 21, one server 1 is prepared in a network and plural CPEs (customer premise equipments) 2a to 2n are prepared, which are devices on the side of clients who receive service, and each of the CPEs 2a to 2n can receive distribution of content data prepared in the server 1. In this example, 14 CPEs 2a to 2n are prepared and seven CPEs 2a to 2g of them are now receiving distribution of content data from the server 1 while the other CPEs are on standby. In this example, only 14 CPEs are used for simplifying the explanation. In many cases of actual distribution of content data, more clients may access the server simultaneously.

"Patent Reference 1 discloses distribution of content data or the like through a communication network such as the Internet.

"Patent Reference 1: JP-A-2003-196491

"Since clients access the server simultaneously, the server bears the burden of calculation and network corresponding to the total number of clients connected thereto. Generally, immediately after the content distribution service is started, many clients make requests simultaneously, and if the server does not have sufficient capability, trouble of server down occurs. If the server has sufficient capability to prevent such occurrence, the cost necessarily increases accordingly. Since the number of requests decreases with the lapse of time from the start of the service, the prepared server capability then turns out to be excessive investment. On the other hand, there also is a possibility that if the service becomes very popular, reinforcement of the server cannot catch up with unexpected increase in the number of requests for the service and server down occurs, losing opportunities of business. In such a content distribution system, for example, the number of expected simultaneous accesses to very popular contents may exceed one million.

"In the example of FIG. 21, the seven CPEs 2a to 2g are receiving the service. In this case, the server 1 bears a load of arithmetic operation for the seven CPEs (often the same load of arithmetic operation as on the individual CPES) and a network load for the seven CPEs. Therefore, a device of higher cost than that of the device on the client side is demanded as the server. In the example of FIG. 21, in the worst cast, capital investment equivalent to the seven CPEs is necessary. Moreover, though the server must have capability to provide service to a statistically calculated maximum number of CPEs (in this case, for example, it is assumed that the maximum number of CPEs that simultaneously access the server is seven), the maximum number is not always reached at the time of ordinary service. If the server provides service to approximately two CPEs on average, the capability to provide service to the other five CPEs is considered to be excessive investment.

"Also, in such content distribution systems, security is often weak. In many cases, in order to reduce the server load and server cost, encryption need not be performed. Therefore, there is a high risk of contents being stolen, and valuable contents are hardly distributed through networks. Even if encryption is performed, it is difficult to encrypt contents for each traffic. Generally, encryption in data distribution is applied only to a small volume of data (text data or the like). AS for large streams, data that have already been encrypted are distributed in order to reduce the cost. In this case, however, many CPEs commonly use the same key. Moreover, the contents are encrypted with the same key for a long period and the same key is sent many times. Therefore, it gives a clue to key analysis and the strength of encryption is low."

In addition to the background information obtained for this patent, VerticalNews journalists also obtained the inventor's summary information for this patent: "A first object of this invention is to enable distribution of contents through a network with reduced load on the server. A second object of this invention is to enable distribution of contents through a network with high security strength.

"According to this invention, on the side of a server connected to a predetermined network, preparation of a content database for managing data related to contents that can be distributed through the network, preparation of a content cluster list containing data related to division of each content managed on the content database into clusters, and preparation of a cluster database related to an address at which each cluster shown in the content cluster list is stored, are carried out, and management of content distribution is carried out on the basis of the data of the prepared databases and list. On the side of a device that can be connected to the server, content saving processing to save at least a part of clusters formed by dividing a received content, by cluster, and cluster data transmission processing to manage a number of the content saved by the content saving processing and a number of the saved cluster and to transfer a predetermined cluster saved by the content saving processing to an address indicated by the server in response to a request for transmission of a cluster of the received content, are carried out.

"As such processing is carried out, it is possible to distributively save content data to a device in the network by each cluster, which is generated by dividing the content. On the side of the device that receives distribution of the content, the address indicated by the server can be accessed to acquire the content data, distributively saved by each cluster.

"According to this invention, it is possible to distributively save content data to a device in the network by each cluster, which is generated by dividing the content. On the side of the device that receives distribution of content, the address indicated by the server can be accessed to acquire the content data, distributively saved by each cluster, and distribution of the content data need not be directly received form the server. When requests for distribution of content data are simultaneously made, access from each device in the network can be dispersed. Even if the server does not have a simultaneous access function of high capability, content data can be distributed simultaneously to many users.

"In this case, the server has an authentication database and the authentication database manages keys to encrypt the individual clusters at each storage place of each cluster indicated by the cluster database. Thus, the content data, distributively stored by cluster at each device, is encrypted with the individual keys, and security strength of the content data is increased.

"Moreover, the data related to division into clusters stored in the content cluster list, the data related to an address at which each cluster is stored, stored in the cluster database, and the data related to encryption keys stored in the authentication database are sent as a cue sheet for reproducing a content, to the side of the device that requests the content data. Thus, the device requesting the content data can distributively acquire the content from the network on the basis of the data indicated on the cue sheet and can carry out decoding and satisfactory processing of the acquired content."

URL and more information on this patent, see: Muraoka, Kazuhiko. Server, Content Providing Apparatus, Content Receiving Apparatus, Content Providing Method, Content Receiving Method, and Program. U.S. Patent Number 8640178, filed July 30, 2004, and published online on January 28, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=11&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=508&f=G&l=50&co1=AND&d=PTXT&s1=20140128.PD.&OS=ISD/20140128&RS=ISD/20140128

Keywords for this news article include: Sony Corporation, Information Technology, Information and Data Encoding and Encryption.

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Source: Information Technology Newsweekly


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