【作者】 李平；

【导师】 卢正鼎；

【作者基本信息】 华中科技大学 ， 计算机应用技术， 2009， 博士

【摘要】 近年来,随着因特网和多媒体技术的迅速发展,用户可以方便地制作数字内容并通过网络进行传播。然而,用户对数字内容的任意复制和传播使得网络上的版权侵害问题非常严重。这极大地损害了版权拥有者及相关权利人的合法权益,妨碍了数字化产业的健康有序发展。因此,如何有效保护数字内容的版权已成为业界所面临的一个重要问题。数字版权管理DRM(Digital Rights Management)作为一个解决该问题的有效技术,受到越来越多研究者的关注。该技术可用以保证数字内容在整个生命周期内的合法使用,平衡数字内容价值链中各个角色的利益和需求。目前,大多数DRM系统都将使用数字内容时必不可少的数字许可证保存在用户端,这会带来一定的安全隐患。此外,现有的DRM系统主要关注权利在版权所有者和普通用户之间的传递,而较少注意权利在普通用户间的二次分发。据此提出一种基于移动代理并支持权利二次分发的DRM系统并对系统的主要工作协议进行了阐述。系统中的移动代理能代表内容服务器的利益,携带数字许可证移动到用户端公正地执行DRM功能,并在执行完毕之后返回发送端,这避免了数字许可证在用户端的存储,而通过将移动代理构建为时限黑箱可保证移动代理自身的安全。系统还提供了对权利二次分发的支持以提高用户购买和使用内容的积极性,减少用户破解DRM系统的可能性。此外,系统还通过在发布的数字内容中嵌入内容服务器的数字水印来进行版权追踪。随着电子产品的普及以及通信技术的发展,家庭网络已经成为研究者关注的热点。家庭网络的独特特点使得目前市场上一般的DRM系统对其并非完全适合,如在家庭网络内,用户一般都希望能实现数字内容的方便共享,而大多数DRM系统对此并不支持。通过对现有的一些面向家庭网络的DRM方案的分析,可以发现它们在权利管理模式、管理的灵活性以及安全性等方面存在一些不足。据此提出一种面向家庭网络的DRM系统并对系统的主要工作协议进行了阐述。系统中,家庭网关通过“域”的构建来管理家庭网络内的所有用户设备,并作为它们的代理向因特网上的DRM服务器申请数字内容和许可证。家庭网关所申请的权利基于家庭网络域内所有用户设备,该权利允许合法注册的用户设备通过超级分发模式进行数字内容的共享,而组密钥技术则可以保证加密的数字内容只能被合法用户设备解密使用。此外,系统在其所发布的数字内容中嵌入家庭网关的数字指纹,这样,系统在发现盗版时可根据该数字指纹来定位具体的家庭网络并依法追究其责任。当前市场上已有的DRM系统数量众多,而这些DRM系统在发布的数字内容和许可证的格式上以及操作方法上均存在着差异,这给用户的内容使用带来了极大的不便,同时也妨碍了市场的进一步发展。解决该问题最主要的方法是采用互操作技术。通过对现有的一些DRM互操作解决方案的分析,发现它们在用户端负载或安全性等方面存在一些不足。据此提出一种DRM互操作支撑系统并对系统中的主要工作协议进行了阐述。系统可连接不同的DRM系统,并通过格式转换来实现DRM系统之间的数字内容访问。系统由可信的专用服务器承担并采用公钥基础设施机制来保证其安全性。分析表明该系统在安全性和工作效率等方面具有一定优势。更多还原

【Abstract】 In recent years, with the rapid development of the Internet and multimedia technique, digital contents can be freely produced and then be propagated through the networks. However, the arbitrary copy and redistribution to the digital contents make the copyrights infringement in the networks very serious. The legal rights of the rights holders and relative people are greatly harmed and it obstructs the digitalized industry in developing healthily and orderly. So, how to protect the copyrights of the digital contents is becoming an important problem to the industry.As an effective technique to solve the problem, DRM (Digital Rights Management) catches the researchers’ more and more attentions. The technique is used to ensure the legal use during the whole life circle of the digital contents, and it can balance the benefits and requirements of each role in the digital content value chain.At present, most DRM systems save the digital license which is necessary while using the digital content in the user end. It would bring some security problem. Besides, the existing DRM systems emphasize the distribution of rights between the rights holders and common users, but pay very little attention to rights redistribution between the common users. A DRM system based on mobile agent for digital rights redistribution is proposed and the main protocols of it are analyzed. In the system, the mobile agent is deployed on behalf of content provider. It carries the digital license and arrives in the user end to enforce the DRM functions honestly, and returns to the sender end after execution, this prevents the digital license from saving in the user end. The security of the mobile agent itself can be assured by creating a time limit blackbox out of an original mobile agent. Rights redistribution supported by the system can increase the motivation for users to buy and use contents and decrease the possibility to crack the DRM system. Besides, the digital watermarking is embedded in the digital content issued by the content provider to copyrights pursuit.With the popularization of the electronic products and the development of the communication technology, home network is becoming a hotspot to the researchers. The unique properties of the home network make the common DRM systems in the market not suitable for it, for example, in the home network, users usually wish the contents can be conveniently shared, but most DRM systems don’t support it. According to the analysis of the existing DRM proposals for home network, we can find that they have some shortages about rights management mode、flexibility of management and security. So a home network oriented DRM system is proposed and the main protocols of it are analyzed. In the system, home gateway manages all the user terminals in the home network by creating a domain, and requires digital content and license from the DRM system in the Internet as their agent. The right required by the home gateway bases on all the user terminals in the home network domain, and it allows the content sharing between the user terminals which have legally registered in the domain through the super distribution mode, and the group key technique can ensure that the encrypted content is only decrypted and used by the legal user terminals. Besides, the system embeds the digital fingerprint of the home gateway. As a result, when the pirated copy of the issued content is found, the digital fingerprint is used in locating the precise home network and investigating it according to law.There are many DRM systems in the market now, but the format of the provided contents and licenses and the operation methods of the DRM systems all exist distinct. It brings huge inconvenience to users and disturbs the further development of the market. The main measure to solve the problem is the interoperability technique. Through the analysis to some current schemes to solving DRM interoperability, we can find them lack in user end burden and security etc. So a supporting system for DRM interoperability is proposed and the main protocols of it are analyzed. The system can connect different DRM systems and apply content access between DRM systems through format conversion. The system is applied by the specific convincing server and adopts Public key infrastructure technique to ensure security. The analysis shows the system has some advantage in security and work efficiency.更多还原