可验证加密签名方案的研究及进展

可验证加密签名方案可用于构建电子商务中优化的公平交换协议。通过对国内外可验证加密签名方案的研究状况进行分析,指出在当前的研究中存在的一些问题,如效率和安全的结合问题、隐私保护等,并通过对Li等人的可验证加密签名进行伪造攻击,说明可验证加密签名方案应满足强不可伪造性,最后,讨论了可验证加密签名的研究中需要解决的一些问题和未来的研究趋势。     

Proactive Weighted Threshold Signature Based on Generalized Chinese Remainder Theorem

This paper proposes a new proactive weighted threshold signature scheme based on Iflene＇s general secret sharing, the generalized Chinese remainder theorem, and the RSA threshold signature, which is itself based on the Chinese reminder theorem. In our scheme, group members are divided into different subgroups, and a positive weight is associated to each subgroup, where all members of the same subgroup have the same weight. The group signature can be generated if and only if the sum of the weights of members involved is greater than or equal to a fixed threshold value. Meanwhile, the private key of the group members and the public key of the group can be updated periodically by performing a simple operation aimed at refreshing the group signature message. This periodical refreshed individual signature message can enhance the security of the proposed weighted threshold signature scheme.     

A multichannel relay MAC protocol for IEEE 802.11 wireless LANs

One of the challenging issues in wireless LANs (WLANs) is improving the network throughput. One of the possible solutions for the issue is maximizing the number of concurrent transmissions. Although some protocols have been proposed to exploit transmission concurrency in WLANs, their performance depends on the degree of the interference among links. Also, it is hard to obtain interference information because of their dynamics. In this paper, we propose an enhanced medium access control (MAC) protocol for WLANs, named multichannel relay MAC (MRMAC), which is able to transmit multiple frames simultaneously without considering interference. To enable concurrent transmissions, MRMAC adopts the concept of frame relaying. Furthermore, MRMAC utilizes several nonoverlapping channels to eliminate interferences. Through extensive simulations, we found that MRMAC shows better performance than existing well‐known MAC protocols. Copyright © 2013 John Wiley & Sons, Ltd.     

一个采用不等式验证方式的数字签名方案

本文提出了一个新的数字签名方案,它通过判定验证值是否满足一个不等式的方式来验证签名的合法性,实质是等式验证的进一步推广.新方案在理论分析上是安全的,并具有较大的实用价值.     

Private Computation: k-Connected versus 1-Connected Networks

We study the role of connectivity of communication networks in private computations under information theoretical settings in the honest-but-curious model. We show that some functions can be 1-privately computed even if the underlying network is 1-connected but not 2-connected. Then we give a complete characterisation of non-degenerate functions that can be 1-privately computed on non-2-connected networks. Furthermore, we present a technique for simulating 1-private protocols that work on arbitrary (complete) networks on k-connected networks. For this simulation, at most additional random bits are needed, where L is the number of bits exchanged in the original protocol and n is the number of players. Finally, we give matching lower and upper bounds for the number of random bits needed to compute the parity function on k-connected networks 1-privately, namely random bits for networks consisting of n players.     

Unifying computers and dynamical systems using the theory of synchronous concurrent algorithms

A synchronous concurrent algorithm (SCA) is a parallel deterministic algorithm based on a network of modules and channels, computing and communicating data in parallel, and synchronised by a global clock with discrete time. Many types of algorithms, computer architectures, and mathematical models of physical and biological systems are examples of SCAs. For example, conventional digital hardware is made from components that are SCAs and many computational models possess the essential features of SCAs, including systolic arrays, neural networks, cellular automata and coupled map lattices.In this paper we formalise the general concept of an SCA equipped with a global clock in order to analyse precisely (i) specifications of their spatio-temporal behaviour; and (ii) the senses in which the algorithms are correct. We start the mathematical study of SCA computation, specification and correctness using methods based on computation on many-sorted topological algebras and equational logic. We show that specifications can be given equationally and, hence, that the correctness of SCAs can be reduced to the validity of equations in certain computable algebras. Since the idea of an SCA is general, our methods and results apply to each of the particular classes of algorithms and dynamical systems above.     

Erratum: Arbitrated quantum signature of classical messages against collective amplitude damping noise (Opt. Commun. 283 (2010) 3198-3201)

We discover an error in the quantum circuit in Fig. 2 in the original paper [Y.G. Yang, Q.Y. Wen. Opt. Commun. 283 (2010) 3198-3201]. Corrected results are obtained and presented in this paper.     

基于小波不变矩的多类目标特征选择算法

特征选择是目标识别中的重要问题。对于有着3个参数（m,n,q）的小波矩来说更是如此。基于2类模式的特征选择思想,提出多类模式下绝对可分的特征选择算法,给出图像数值化处理中参数(m,n,q)的合理取值范围。实验结果表明：无论是对差别比较大、差别比较小还是混合型的多类目标,经过此特征提取出来的小波矩都有着较好的识别效果。     

利用RSA密码体制解决安全多方多数据排序问题

 本文研究了姚氏百万富翁问题的一个推广问题,安全多方多数据排序问题:假设有n方P₁,P₂,…P_n,他们分别拥有一个保密数据集D_P1,D_P2…D_Pn{1,2,…,N}.我们对这多个数据集的并集D=D_P1∪D_P2∪…∪D_Pn中所有的数据进行一个安全的排序,要求在排序结束后各方能够知道他们各自拥有的数据在D中的次序,并且任意一方都不知道其它方拥有的数据的任何信息.我们提出了一个基于RSA同态密码体制的解决安全多方多数据排序问题的方案,并在半诚实模型下对该协议的正确性、安全性和效率进行了分析.     

Secure proxy signature scheme with fast revocation in the standard model

proposed scheme is provably secure based on the computational Diffie-Hellman (CDH) intractability assumption without relying on the random oracles, and satisfies all the security requirements for a secure proxy signature.