基于PCM/PPK遥测体制的钟控序列加密方案及系统仿真

PCM/PPK telemetry system is a multinary pulse modulation system. It is commonly used to transmit high-accuracy time information and some express signals. To the issue of security that telemetry data is transmitted in the open space, a data encryption scheme in the PCM/PPK telemetry system is proposed. In this scheme, the PCM data of signal source are encrypted by stream cipher in which key streams are generated with clock control LSFR. The scheme can save system resource in the dual-modulation compound telemetry system. A backward key synchronization scheme is also proposed, which has the property of strong real-time and easy to implement. A simplified simulation model of PCM/PPK remote system is established based on the actual framework of telemetry system, and the model is simple and easy to simulate. The error performance of the system is analyzed in theory and tested by computer simulation. Also the security of the system is analyzed. The simulation and analysis results show that the encryption scheme can ensure the security of the telemetry data and does not cause error-diffusion.     

基于UDP的室内无线接收DVB方案研究

随着智能移动设备的广泛普及,家庭用户逐渐渴望能够在智能终端上收看数字电视节目。由于传统家庭内部的机顶盒只能提供有线数字电视信号,因此本文研究了一种基于UDP协议的室内无线接收DVB-C信号的方法,并分析了MPEG-2 TS的相关原理及室内无线传输损耗,在此基础上讨论了方案的可行性。     

基于Radix-4 Booth编码的模2n+1乘法器设计

模2n+1乘法(n=8、16)在分组密码算法中比较常见,如IDEA算法,但由于其实现逻辑复杂,往往被视为密码算法性能的瓶颈。提出了一种适用于分组密码算法运算特点的基于Radix-4 Booth编码的模2n+1乘法器实现方法,其输入/输出均无需额外的转换电路,并通过简化部分积生成、采用重新定义的3-2和4-2压缩器等措施以减少路径时延和硬件复杂度。比较其他同类设计,该方法具有较小的面积、时延,可有效提高分组密码算法的加解密性能。     

聚氨酯泡沫富集-ICP-AES法测定土壤及水系沉积物中铊含量

本文建立了一种以聚氨酯泡沫富集-ICP-AES法测定土壤及水系沉积物中铊含量的分析方法,利用正交实验,确定最佳实验条件,方法的检出限为0.01mg/L,经对土壤及水系沉积物成分分析标准物质的检测,结果与推荐值相符,相对误差小于10%,相对标准偏差(RSD,n=10)在1.9%-4.9%之间。     

IPTV码流监测系统的设计与实现

为确保IPTV的安全播出和服务质量(QoS),需要对IPTV关键节点进行码流监测,同时监测的告警信息要准确、及时地通知相关技术人员,以便问题的快速定位和故障排除.为此,详细介绍了广州珠江数码集团有限公司IPTV码流监测系统的设计及主要实现的功能.     

对7轮ARIA-192的不可能差分分析

ARIA密码是2003年由韩国学者提出的新的分组密码算法,该密码与AES的设计原理相类似,并在2004年被选为韩国的分组密码标准。该文根据ARIA密码的结构特征,提出ARIA密码的一种新的7轮不可能差分攻击路径,首次实现了对ARIA-192的不可能差分攻击,攻击的时间复杂度为2176.2。同时,利用扩散层的相关性质降低攻击ARIA-256的时间复杂度为2192.2。     

Crypto-analysis of the Encryption Algorithm Rijndael

1　ＩｎｔｒｏｄｕｃｔｉｏｎＲｉｊｎｄａｅｌｉｓａｋｉｎｄｏｆｉｔｅｒａｔｅｄｂｌｏｃｋａｌｇｏｒｉｔｈｍｄｅｖｅｌｏｐｅｄｂｙＢｅｌｇｉａｎｃｒｙｐｔｏｇｒａｐｈｅｒｓＪｏａｎＤａｅｍｅｎａｎｄＶｉｎｃｅｎｔＲｉｊｍｅｎｉｎｏｒｄｅｒｔｏｒｅｓｐｏｎｄｔｈｅｃａｌｌｏｆＮＩＳＴｆｏｒａｄｖａｎｃｅｄｅｎｃｒｙｐｔｉｏｎｓｔａｎｄａｒｄ (ａｎｅｗｓｕｂ ｓｔｉｔｕｔｅｆｏｒＤＥＳ) .Ｒｉｊｎｄａｅｌｉｓ,ｉｎｆａｃｔ,ａｖａｒｉａｎｔｏｆａｎｏｔｈｅｒａｌｇｏｒｉｔｈｍｃａｌｌｅｄＳｑｕａｒｅ ,ｗｈ…     

On Annihilators in Fewer Variables： Basic Theory and Applications

Algebraic attacks on stream ciphers exploit annihilators of low degree. From another point of view, we concentrate on annihilators in fewer variables in this paper. This work consists of two parts. Firstly, the concept of singular annihilators is proposed and the basic theory is established. Secondly we present two applications of singular annihilators. We propose a variant of the Filter states guessing attack （FSGA） introduced by Pasalic （2009）. Our attack outperforms the FSGA in many cases. Moreover, we put forward a probabilistic algorithm, which can screen out a large number of Boolean functions with annihilators of low degree at a lower cost for the resistance against algebraic attacks.