【摘要】 部分加密等媒体数据加密算法是保护媒体数据安全的有效方法,但用其加密流媒体系统中的多路媒体数据将使系统面临效率、规模扩展与安全性问题.为此提出基于数据安全权重的多数据流加密的动态最优选择控制模型,根据各数据流的带宽、权重等参数,为不同数据动态选择不同强度的加密方法.由于化简后的数学模型是NP难的0-1背包问题,结合实际系统特点提出基于贪婪启发思想的增量式近似算法.理论分析和实验表明该算法时间复杂度低且具有良好的近似性.最终在一个实用流媒体系统———Adm ire系统中设计实现了选择控制模型的原型子系统.更多还原

【Abstract】 Partial encryption and other media encryption schemes are effective approaches to encrypt the media data which are high volume and latency sensitive.However,use one media encryption scheme to protect all the media streams in a streaming media system will induce efficiency,scalability and security problems.To solve this problem,a security weightiness based dynamic optimal selective control mechanism for multi-datastream encryption was proposed.The idea of partial encryption was generalized from encrypting a subset of one stream to multi-streams.It can determine the optimum encryption algorithm with different security levels for each stream in the system,according to stream’s bandwidth,weightiness and other parameters.Since the simplified mathematical model is 0-1 knapsack problem which is NP-hard,a greedy heuristic incremental approximate algorithm was designed.Theoretical and experimental analyses show the approximate rate and speed of the algorithm are effective enough to support real-time applications.A prototype was implemented in an actual video conferencing system: Admire.更多还原