A secure proxy signature scheme based on elliptic curve cryptosystem

Proxy signature is a special digital signature which enables a proxy signer to sign messages on behalf of the original signer. This paper proposes a strongly secure proxy signature scheme and a secure multi-proxy signature scheme based on elliptic curve cryptosystem. Contrast with universal proxy signature schemes, they are secure against key substitute attack even if there is not a certificate authority in the system, and also secure against the original signer＇s forgery attack. Furtherlnore, based on the elliptic curve cryptosystem, they are more efficient and have smaller key size than other system. They can be used in electronics transaction and mobile agent environment.     

Provable secure proxy signature scheme without bilinear pairings

Proxy signature is an active research area in cryptography. A proxy signature scheme allows an entity to delegate his or her signing capability to another entity in such a way that the latter can sign messages on behalf of the former. Many proxy signature schemes using bilinear pairings have been proposed. But the relative computation cost of the pairing is more than 10 times of the scalar multiplication over elliptic curve group. In order to save the running time and the size of the signature, we propose a proxy signature scheme without bilinear pairings and prove its security against adaptive chosen‐message attack in random oracle model. The security of our scheme is based on the hardness of the elliptic curve discrete logarithm problem. With the running time being saved greatly, our scheme is more practical than the previous related scheme for practical applications. Copyright © 2011 John Wiley & Sons, Ltd.     

一种强不可伪造无证书签名方案的密码学分析与改进

无证书密码体制是无线网络中一种非常有效安全保护工具.2016年,Hung等人提出了标准模型下一种强不可伪造性的无证书签名方案,该方案声称在抗哈希碰撞问题和计算Diffle-Hellman困难问题假设下是安全不可伪造的.事实上,该方案对类型II敌手是不安全的.本文给出对Hung等的方案的安全性分析,并证明对于类型II敌手可以伪造出合法签名,针对存在问题提出一种改进的无证书签名方案.     

移动社交网络多密钥混淆的交友隐私保护方案研究

在移动社交网络中,为保证交友匹配过程中用户的隐私,提出多密钥混淆隐私保护方案.利用代理重加密技术,对用户密钥密文进行重新加密,实现了以扩充交友访问策略条件的交友匹配,并保证密文转换过程中用户的隐私不被泄露;利用随机密文组件加密技术,实现了对真实明文对应加密文件的信息隐藏,提高了攻击者的破解难度;利用数据摘要签名技术,解决了以往方案未考虑的多加密文件对应的文件解密问题.安全和实验分析表明,本文方案可以达到CPA（Chosen Plaintext Attack）安全,可以保证交友用户的隐私不被泄露,并且比既有的方案更有效.     

An authenticated re‐encryption scheme for secure file transfer in named data networks

With the fast progress of the Internet and communication technologies, the digital communication is increasingly based on the architecture of TCP/IP. Nevertheless, in TCP/IP's architecture, there are limitations such as data uncertainty and flow overloading. In response to this, a novel architecture has been proposed, which is known as the named data network (NDN). Named data network is an alternative network architecture based on the data each user accesses. Users gain accesses to the data by using an adjacent router (node) that verifies the correctness of the data. In NDN, the router has the capability to store and search for the data. Hence, this architecture largely improves the disadvantages in TCP/IP's architecture. Named data network is a new proposal and relatively under‐researched now. Thus far, an adequate secure file transfer protocol is still unavailable for NDN. In some cases, files are broken or the source fails to authenticate, which results in the need to discover the owner of the file. Furthermore, we believe that NDN should involve an authentication mechanism in the secure file transfer protocol. In view of the above, this paper presents an authenticated re‐encryption scheme for NDN, which offers sender authentication, data confidentiality, and support for potential receivers. Finally, we also propose a security model for sender authentication and prove that the proposed scheme is secure.     

空间探测激光距离多普勒雷达系统原理设计

以激光距离多普勒成像雷达系统（LRDIR）能够提取空间目标激光散射信号特征,判断空间目标在轨运行姿态为应用背景,给出了激光距离多普勒成像激光雷达系统设计的一般原理,并指出系统重要组成部件,在信号检测过程中所起的作用.结合相关实际测量材料的试验数据和器件性能参数,分析系统性能和各种干扰噪声,并计算系统在探测单元和探测阵列两种情况下,信噪比随探测距离和接收器口径的变化规律,为具体工程应用提供可靠的依据.     

基于AODV的能量有效路由协议

通过对AODV路由协议进行改进，提出了基于AODV的能量有效的路由协议（EE—AODV）。新协议考虑了节点的剩余能量，根据节点的剩余能量调节RREQ延迟来平衡节点的能量消耗，利用节点最近一次传递过数据分组的时间作为约束条件来优化RREQ的洪泛广播，降低网络的能量消耗。仿真结果表明．和AODV路由协议相比，新协议降低了网络的能量消耗并减少了耗尽能量的节点数，延长了网络的生存时间。     

Analytical Expression of the Threshold Pump Power of Erbium—doped Fiber Laeers Pumped at 980 nm and 1480nm Wavelengths

The rate equations,which is suiable to erbium-doped fiber lasers pumped at 980 nm and 1480 nm wavelengths respectively,are investigated,and analytical ex-pressions of the threshold pump powers under two pump wavelengths are derived.As a result,some important parmeters can be quantitatively specified.     

坦克红外特征控制技术评述

坦克红外特征控制对于提高坦克的战场生存能力具有重要意义。控制的主要方法有遮障、表面处理、外形技术、主动冷却、总体设计等。坦克红外特征的控制必须与其他波段，特别是射频波段的特性控制兼容。遮障和低发射率涂料是现役坦克红外特征控制的主要措施。而对未来的主战坦克，设计应是减少其系统特性的重要途径。     

微波检测模块

从微波电路、运放及数字电路、脉冲检测等方面介绍了微波检测模块，给出了有关数据并对问题进行了讨论。