To deliver an encrypted digital content to a client device without sharing of secret information by a plurality of content servers and a plurality of license servers.
An encrypted content obtained by encrypting a digital content by use of a common key by a common key encryption method is stored in a content storage server in conformation to an encrypted common key obtained by encrypting the common key by use of an identifier of the digital content and disclosed information issued by a license server, and license location information showing the location of the license server which issued the disclosed information and content location information showing the location of the content storage server storing the digital content are stored in a content delivery control server in conformation with the identifier. The content delivery control server transmits, on receipt of a delivery request of the digital content with the set identifier from a client device, the license location information and content location information corresponding to the identifier to the client device.
COPYRIGHT: (C)2006,JPO&NCIPI
Takaaki Yamada
Eriko Ikeda
Keigo Mashima
Ogawa alone
Arisa Fujii
Takeshi Otake
Goichiro Hanaoka
日本放送協会
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