共查询到19条相似文献,搜索用时 93 毫秒
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条件接收系统是实施收费数据广播业务平台中的重要组成部分,为了实现基于DVB单向传输网络下的条件接收系统中授权问题,提出引入智能密码钥匙(USBkey)作为单向数据传输的终端用户身份认证及权限接收工具,提供一种采用对称密码体制和非对称密码体制结合安全认证方案,以实现单向传输过程中的高安全性和实时性需要。该方案在央视数据广播的条件接收系统中得以成功的实施。 相似文献
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本文首先介绍了DVB条件接收系统的发展现状以及基本原理,然后针对机卡分离的DVB—CI通用接口技术和通用接口协议栈作了详细的阐述,对其接口从应用层到底层的协议特性和功能进行了分析和研究,并提出了通用接口的软件设计方法,实现数字电视条件接收功能,指明了DVB通用接口在条件接收系统中的作用重要性和广阔的应用前景。 相似文献
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该文介绍了DVB-T和条件接收的基本工作原理,并在此基础上对基于DVB-T的PCTV条件接收系统进行了设计,并给出了各模块的相关软件设计。此系统基本上实现了对DVB-T信号的调谐和解调,经测试,能通过第三方player清晰流畅的播放透明的以及加扰的节目。 相似文献
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可下载条件接收系统(DCAS)是一种双向认证授权体系,条件接收(CA)算法和密钥可以动态下载.随着互联网和数字电视为代表的数字化内容越来越丰富,条件接收系统(CAS)不断向可下载的条件接收系统(DCAS)转变已是大势所趋.本文回顾总结了主要的DCAS技术发展并对中国的DCAS发展趋势进行了展望. 相似文献
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该文介绍了DVB—T和条件接收的基本工作原理,并在此基础上对基于DVB-T的PCTV条件接收系统进行了设计,并给出了各模块的相关软件设计。此系统基本上实现了对DVB—T信号的调谐和解调,经测试,能通过第三方player清晰流畅的播放透明的以及加扰的节目。 相似文献
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本文针对数字电视等多媒体通信系统,提出了一个以密码算法为核心的三级加密条件接收系统(CAS),介绍了模型工作原理和系统结构,分析了.CAS系统中的数据加扰、AES加密和RSA加密的原理及实现方法.最后在结束语部分给出了性能分析,指出该条件接收系统能很好的应用与数字电视、IPTV等,从而提高整个通信网络和系统的安全性和效率. 相似文献
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介绍数字电视产业中机卡分离的必要性,阐述了采用PCMCIA接口技术的产业优势,提出了基于嵌入式系统、以DVB-CI为标准的机卡分离软件系统设计方案,以构件化、层次化为基本设计思想,通过在物理层、连接层、传输层等不同层次之间定义统一的硬件和软件规范,对不同CA系统异性特征进行隔离并分别封装在传输与命令处理组件中,提供了可适应多种CA系统运行的机顶盒接口统一解决方案。 相似文献
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具有时态特征的角色访问控制(RBAC:Role Based Access Control)模型能够为RBAC控制机制提供动态的时间控制因素,是目前安全模型领域的研究热点。基于对周期理论和时态RBAC模型的研究,本文认为时态不仅能够为模型提供时间维的控制因素,而且模型中的约束也能作用于时间雏形成条件时态平面的控制因素,从而能够进一步提高模型控制的灵活性和多样性。为此,本文提出了条件周期表达式和条件时态的概念,形式化描述了条件时态语义;并通过条件周期事件和角色状态在条件周期下的断言详细论述了条件时态。 相似文献
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本文首先介绍了DVB条件接收系统的发展现状以及基本原理,然后针对机卡分离的DVB-CI通用接口技术和通用接口协议栈作了详细的阐述,对其接口从应用层到底层的协议特性和功能进行了分析和研究,并提出了通用接口的软件设计方法,实现数字电视条件接收功能,指明了DVB通用接口在条件接收系统中的作用重要性和广阔的应用前景。 相似文献
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This paper presents a role-involved purpose-based access control (RPAC) model, where a conditional purpose is defined as the intention of data accesses or usages under certain conditions. RPAC allows users using some data for a certain purpose with Conditions (For instance, Tony agrees that his income information can be used for marketing purposes by removing his name). The structure of RPAC model is investigated after defining access purposes, intended purposes and conditional purposes. An algorithm is developed with role-based access control (RBAC) to achieve the compliance computation between access purposes (related to data access) and intended purposes (related to data objects). Access purpose authorization and authentication in the RPAC model are studied with the hierarchical purpose structure. According to the model, more information from data providers can be extracted while at the same time assuring privacy that maximizes the usability of consumers’ data. It extends role-based access control models to a further coverage of privacy preservation in database management systems by adopting purposes and conditional intended purposes and to achieve a fine-grained access control. The work in this paper helps enterprises to circulate a clear privacy promise, and to collect and manage user preferences and consent. 相似文献
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This paper presents a model for privacy preserving access control which is based on variety of purposes. Conditional purpose is applied along with allowed purpose and prohibited purpose in the model. It allows users using some data for certain purpose with conditions. The structure of conditional purpose-based access control model is defined and investigated through dynamic roles. Access purpose is verified in a dynamic behavior, based on subject attributes, context attributes and authorization policies. Intended purposes are dynamically associated with the requested data object during the access decision. An algorithm is developed to achieve the compliance computation between access purposes and intended purposes and is illustrated with Role-based access control (RBAC) in a dynamic manner to support conditional purpose-based access control. According to this model, more information from data providers can be extracted while at the same time assuring privacy that maximizes the usability of consumers’ data. It extends traditional access control models to a further coverage of privacy preserving in data mining atmosphere. The structure helps enterprises to circulate clear privacy promise, to collect and manage user preferences and consent. 相似文献
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In this paper, we consider the problem of combining the local conditional distributions of a random variable which have been generated by local observers having access to their private information. Sufficient statistics for the local distributions are communicated to a coordinator, who attempts to reconstruct the global centralized distribution using only the communicated statistics. We obtain a distributed processing algorithm which recovers exactly the centralized conditional distribution. The results can be applied in designing distributed hypothesis-testing algorithms for event-driven systems. 相似文献