排序方式: 共有50条查询结果,搜索用时 575 毫秒
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电视的加密按图像的传送方式可分为模拟图像的加密和数字图像的加密。模拟图像的加密主要有二类:一类是在发射端直接改变图像信号或已调图像信号的某一波形,寻址和控制信息采用数字信号同时传送,在接收端解密后重新恢复图像信号。这类方法必须会对图像质量产生一定的影响,目前较少使用;另一类是在发射端先使用A/D将模拟图像信号转换为数字电视信号,然后对数字信号加扰,同时所有控制信息、授权信息插入 相似文献
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结合文件加密的工作原理,分析了仿射变换加密算法的基本原理,描述了利用仿射密码实现文件加密与解密的方法,从而保障了文件传输的安全性。经过测试证明,该方法达到了文件安全传输的预期效果。 相似文献
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保护设计避免被克隆、反向工程和篡改在现今日益趋向超连接的世界(hyper-connected world)中,如何保护新的设计避免被克隆、反向工程和/或篡改是一项重大挑战。FPGA器件通过加入满足器件级安全需求的特性,来帮助实现这些目标。 相似文献
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程鹏 《电脑编程技巧与维护》1999,(8):63-65
出于对数据安全保护的需要,一个好的密匙系统是必不可少的。这里介绍的时效性密匙有随时间动态变化的特点。它通过一种特殊算法以当前系统日期作为种子值经过不可逆变换产生一个暂时性密匙,一旦系统日期改变,密匙也随之改变。时效性密匙系统适合于基于服务器——工作站模式的网络保护工作,尤其在以下两种情况下:其一,需要严密保护的数据 相似文献
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Wang Changji Yang Bo Wu Jianping 《电子科学学刊(英文版)》2005,22(5):485-489
In 1999, Seo and Sweeney proposed a simple authenticated key agreement protocol that was designed to act as a Diffie-Hellman key agreement protocol with user authentication. Various attacks on this protocol are described and enhanced in the literature. Recently, Ku and Wang proposed an improved authenticated key agreement protocol, where they asserted the protocol could withstand the existing attacks. This paper shows that Ku and Wang's protocol is still vulnerable to the modification attack and presents an improved authenticated key agreement protocol to enhance the security of Ku and Wang's protocol. The protocol has more efficient performance by replacing exponentiation operations with message authentication code operations. 相似文献
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WANG Lin ZHUANG Yan-bin ZHENG Cheng-zeng 《中国矿业大学学报(英文版)》2007,17(2):277-280
A video patrol and inspection system is an important part of the government's shipping channel information management. This system is mainly applied to video information gathering and processing as a patrol is carried out. The system described in this paper can preview, edit, and add essential explanation messages to the collected video, data. It then transfers these data and messages to a video server for the leaders and engineering and technical personnel to retrieve, play, chart, download or print. Each department of the government will use the system's functions according to that department's mission. The system can provide an effective means for managing the shipping enterprise. It also pro- vides a valuable reference for the modernizing of waterborne shipping. 相似文献
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