デジタルコンテンツ流通の収益モデルの研究 : DRM技術と課金決済方式

抄録

This paper argues the content distribution through digital telecommunication network, focusing on the billing method for customer. For this purpose, author describes two (2) kinds of billing methods such as pre-usage billing method and post-usage billing method. The pre-usage billing method means the royalty fee is fixed and charged before the consumer uses the content. In turn, the post-usage billing method means total amount of royalty fee is calculated and charged after the consumer uses the content. The author shows, the representative examples of electronic copyrights management system (ECMS), Kitagawa's "copymart" and Mori's "superdistribution" are interpreted as the basic type for pre-usage billing method and post-usage billing method. The DRM (Digital Rights Management) technology is the clusters of element technology such as global unique identifier for content, encryption, decryption, private key management, billing management, transmission of copy control information and rights management information. This information technology enables to implement the copyrights protection and the mechanism for gaining the royalty fee for content by the electronic commerce. The preconditions of DRM technology for pre-usage billing method and post-usage billing method are not equal. The precondition for pre-usage billing method meets the conformance of copyrights protection against illegal copy. The precondition for post-usage billing method means the monitoring the usage of content or retrieving the usage records for each consumer. The protect-packaged content generated by raw content with DRM technology can possess new property for each consumer, such as number of copy and number of replay. Based on the efficacy of DRM technology, the protect-packaged content is classified the four (4) types of property: the number of infinite-copy and infinite-replay, the number of infinite-copy and fmite-replay, the number of finite-copy and infinite-replay, the number of finite-copy and finite-replay. These four types of protect-packaged content can be corresponded to the pre-usage billing method and/or post-usage billing method. Some case studies shows real correspondence between them.