【作者】 段先德；

【导师】 王宏远；

【作者基本信息】 华中科技大学 ， 通信与信息系统， 2005， 硕士

【摘要】 付费电视和数据广播被认为是广电网络发展的动力和方向,开展付费电视和数据广播业务的一个基本特点就是有效控制、有偿服务。为使广电产业健康良性发展,有线电视系统必须引入条件接收技术。同时条件接收系统又是数字电视综合利用的重要组成部分,如点播电视、电子商务、连接Internet 等都需要计费、收费管理,所以条件接收技术已成为当今广播电视领域科研单位和公司研究和开发的热点。本文主要研究了数字电视条件接收系统的基本原理和在DVB-C 机顶盒上的实现。文中首先介绍了条件接收系统的发展历史和现状,阐述了条件接收系统对于数字电视系统的重要性。然后文章简要地分析了条件接收系统相关的国际标准和中国条件接收系统规范,并简明介绍了智能卡信息传输协议和DES 和RSA 加密算法。接下来文章细致研究了典型条件接收系统的框架和工作流程,分析了数字电视加扰与解扰、加密与解密的流程,并着重分析了条件接收系统中的若干关键技术,如密钥分发管理技术,EMM、ECM 的生成和插入技术,IC 卡的应用技术等。文章还结合笔者参与的具体的条件接收工程项目,详细地介绍了在QAMi5516 平台上实现中视联公司的ChinaCrypt 条件接收系统的方法和过程,描述了各个功能模块的分析、设计、调试和测试环节,并列举了在实现过程中遇到的几个实际问题和解决的办法,最后对系统的安全性进行了分析和评价。文章最后预测了条件接收系统技术将朝着更灵活、更开放、更安全的方向发展,特别介绍了广为关注的机卡分离技术的大致框架。更多还原

【Abstract】 Pay-TV and data broadcasting are considered to be the future direction and momentum of TV broadcasting networks. But controllable and payable service is the basic qualification to develop pay TV and data broadcasting business. In order to develop TV business well, we must fetch in the condtional access system (CAS), In the other hand, CAS is also an important part of integrated using of digital TV, for example, Video on Demand business, electronics commerce business, Internet connect business also need charge counting and management. So CAS has become to be a research and development hotspot in many academe and companies in TV fields. The thesis mainly studies the basic principle of CAS and its implementation of on DVB-C Set Top Box (STB). The developing history of CAS and its current situation are introduced firstly. Then some CAS related international standards and Chinese national standards are briefly described, and smart card communication protocol , encryption arithmetics like DES and RSA are simply introduced . Then the framework and work mechanism of the CAS are analysed, and the encryption and decryption procedure of CAS are discussed, too. Especially, some key technologies in CAS are describled throuthly, such as the key distribution and management technology, the entitlement control message (ECM) and entitlement management message (EMM) generation and plugging technology, the Application of IC card technology. As the project instance, the thesis introduces the design and implementation of ChinaCrypt’s CAS on the DVB-C STB based on the QAMi5516 platform, and detailedly describes each module of the software system, and mentions some difficulties and their settlements in the development. Finally, the thesis gives a comment to the security of the CAS. By the end of this thesis, the author forecasts the future CAS technology will be more flexible, exoteric and securer. Furthermore the thesis describes the rough framework of Removable-Card technology which has received a great attention.更多还原