A Study for License Distribution Mechanism using Accumulated Device Identifier in DRM system

Superdistribution is required in many DRM systems that require rapid and smooth distribution. However, current superdistribution mechanisms do not appear to support certain user needs for contents use. In this paper, we enhance superdistribution to endow it with contents flexibly, and propose a license distribution mechanism to distribute contents securely in the superdistribution. The contents encryption key is encrypted using device identifier of consumer who is superdistributed lastly. The encrypted key is connected to some accumulated device identifiers of consumers. These perform superdistribution in the proposed method. In evaluation, we compared the proposed method with that of the existing DRM systems, and believe to have demonstrated that the proposed method results in increase flexibility for contents use.