Reverse Analysis And Re-Engineering For Open Source DRM System

With the wide use of Internet and the improvement on Streaming Media Technology and compression technology, information like digital book, digital music, movie, image, games can be distributed to end-users. Yet, since those content are easy to be reproduce, alter and distribute, problems like copyright pirate for those content have emerged, posing pressing threat for the copyright for the author and producer of those digital products. Thus, it is highly necessary for us to take effective measures to protect digital content illegal access to without authorization and manage the legal use for those digital products in terms of protecting commercial copyright and detect digital pirate.Digital Rights Management (DRM) is to control the digital content throughout its life circle through combining hardware and software mechanism for store and read. Specifically, such control includes description, detection, exchange for copyright, track for different rights in the use of both physical and immaterial assets, management for relationship of copyright owner and so on. The primary objective of DRM is to protect digital content form online pirate and distribution without authorization, and to control the use of digital content in networkenvironment.With more complex function and larger scale of the software system, original software system products have already not satisfied the modern demand. Since that, we advance the concept of "Software Re-engineering ". As the "software crisis" facilitated the regard of the "software engineering", the software renovation improves the research and development of the "Software engineering". Software re-engineering which falls into the scope of software maintenance is an important component of software engineering. Through analysis and research of the activities and method of software re-engineering, we can learn about how to reuse existed software system and comprehend that reusing is core of the re-engineering.This paper deeply analyzes theory and system structure of DRM technique, explores the realization technique of digit copyright management, compares correlative international criteria and regulations, and analyzes the architecture and code of the open source program OpenIPMP. As the development is based on the existed DRM system, the re-engineering OpenIPMP system utilizes the theory of software re-engineering. Firstly reversely engineer the OpenIPMP system, summarize the class diagrams and use case diagrams based on the deep analysis of architecture of the system. Next, based on the reverse analysis, realize and development the DRM system which can support text format.