【作者】 陈昭智；

【导师】 郑建德；

【作者基本信息】 厦门大学 ， 计算机应用技术， 2006， 硕士

【摘要】 随着Internet的发展,多媒体信息越来越丰富,同时多媒体信息也不可避免地面临着版权保护的问题,迫切需要多媒体数字版权管理系统(DRM)来保障版权拥有者的合法权益。基于无状态的广播加密算法能够非常直观地构建DRM系统。但目前应用较广的广播加密方案中用户持有的密钥为对称密钥,密钥发布中心、消息发布中心和用户持有同一对称密钥,其导致了用户密钥的安全性问题,并且多个消息发布方不能采用同一用户的同一密钥。公钥密码体制的引入可解决上述问题,但是一般公钥密码体制只能应用于广播加密中的CS方案,而效率更高的SD和LSD方案则需要使用基于身份的HIBE的加密方案。本文首先利用基于X509证书的广播加密的完全子树(CS)方案设计并实现了一个灵活、安全的视频数字版权管理系统。本文同时利用基于Weil配对性质的HIBE算法,利用子集覆盖框架下的完全子树(CS)方法构造了一种基于身份的广播加密方案。该方案使用用户的身份作为加密的公共密钥,因此无需单独的公钥/证书发布系统。同时该算法利用HIBE中的层次密钥算法,使得用户所需的私钥存储空间从logN减少到1。本文同时对该方案的安全性、效率和动态可扩展性进行了讨论和分析。本文同时将最新的恒定密文长度HIBE方案中的密钥生成方法和加解密方法进行改造,使之能够应用于广播加密中的子集差分(SD)方案中,并对其进行安全性分析。更多还原

【Abstract】 With the success of the Internet, Multimedia applications and compression technology make great improvements. The security issue of Multimedia becomes more and more important. The digital rights management (DRM) is a good framework to solve the security problem and protect the copyright of multimedia.The stateless Broadcast Encryption scheme can be directly designed to build a DRM system.Most of the Broadcast Encryption schemes for stateless receivers are designed to work in symmetric key setting. Key Distribution Center, Message Distribution Center and Client User all have to keep the same symmetric keys, which leads to the problem of key compromise. Building a public key broadcast encryption scheme is a good solution to this problem. However, the common public key schemes are fit only for Complete Subtree method in Broadcast Encryption. The more elegant SD/LSD methods using public key scheme will result in an enormous public key and very large storage for every user. The Hierarchical Identity-Based Encryption can reduce the public size and user’s storage when it is used in SD/LSD methods.Based on the stateless broadcast encryption scheme with Complete-Subtree method using the X509 certificate, this paper discusses the design of a secure Multimedia system and implements a scalable, flexible and more robust DRM system for Multimedia.And we designed an ID-based broadcast encryption scheme using the latest HIBE algorithm based Weil Pairings and the complete subtree method under the subset cover framework. In this scheme, user’s ID is used as public key for encryption. So the Public Key/Certificates Distribution System is not necessary. And the number of private keys which users have to keep can be reduced from O(logN) to O(1), because of the key hierarchical generation in HIBE algorithm. Finally the cryptanalysis and the discussion of efficiency and dynamic extensibility are given as well.And We bring the latest and efficient HIBE scheme, which has the constant size cipher text, to SD method and demonstrate the modified HIBE scheme which makes更多还原