一个基于两大难题的数字签名方案

指出文献[2]的验证算法是有问题的,同时在文献[2]的基础上提出了一个新的签名方案,其安全性也是基于因数分解和离散对数的,并证明了它的合理性、安全性。     

具有消息恢复的数字签名方案

本文设计一种新的具备消息自动恢复特性的数字签名方案,这种方案的安全性同时建立在因子分解和离散对数之上,并对这种方案进行了安全性分析.     

基于两个数学难题的签名方案

Z.Shao提出了两种签名方案,并宣称它们的安全性是基于大数分解问题和离散对数问题的。其实,这两种签名方案在代换攻击下是不安全的。本文给出了伪造签名的公式,同时还提出了几种带有信息恢复功能的签名方案,它们的安全性是基于上述两个难题的,并且,它们在实施中的效率要比现有的方案好。     

一种新的高效率无证书签名方案

针对无证书签名方案普遍存在执行效率低下的问题,在无证书公钥密码体制下给出一种新的高效率签名方案,并在随机预言机模型下基于离散对数困难问题证明了其安全性。新方案避免使用双线性对运算、指数运算并且使用一般的hash运算替代映射到点的hash运算,提高了运算效率;新方案的签名长度仅为2个整数点长度,通信效率较高。性能分析表明,新方案在保证安全性的前提下具有较高的执行效率,适用于带宽和能源受限的Ad hoc网络等。     

基于ELGamal签名方程的盲签名方案

进一步完善ELGamal盲签名体制，研究了基于ELGamal签名方程的盲签名方案。概述了盲签名的定义及其分类标准，基于不同的签名方程，和有限域上离散对数难解性假设，得到了相应的强盲签名和弱盲签名方案。首次系统地对不同的ELGamal签名方程进行了盲性研究，并对每个盲签名方案进行了盲性分析和安全性分析。     

一个基于两个数学难题的签名方案的分析

分析了文献[4]中提出的基于大数分解和离散对数难题的签名方案,指出文献[4]中提出的方案在离散对数可解时即是不安全的。     

一种新的缩短RS码迭代译码方案

为了在EPON中应用GF(256)标准RS码对信息帧长大于255位的信息流进行编码,并提高RS码的编码增益,提出了一种新的缩短RS码的编译码方案。该方案通过两个缩短RS码的交叠编码和互相迭代译码,可以提高编译码增益。RS码BM硬判决译码和chase软判决译码的计算机仿真表明,该方案对缩短RS码的软硬判决译码性能都有明显提高。     

Turbo码与数字图像传输系统的结合方案探讨

本文研究了Turbo码与数字图像传输系统的结合方案。将Turbo码应用到采用MPEG—2标准的数字电视传输系统的信道编码中,并将Turbo码与RS码的级联方案进行了探讨。对探讨结果进行了计算机仿真,得到了相应的性能曲线。     

具有前向安全性质的秘密共享方案

由于已有的秘密共享方案都不具有前向安全的性质,该文基于有限域上离散对数难解问题和强RSA 假设,应用前向安全理论和已有的秘密共享方案特别是Boyd提出的乘法门限方案的思想,提出了一种具有前向安全特性的秘密共享方案。该方案具有子密的可验证性,能够检测伪子密,防止欺诈者;具有子密更新简便及更新后的子密的可验证性;具有秘密恢复快捷且能直接恢复时间周期j 的秘密信息及检测恢复得到的秘密信息是否正确等功效。该文同时还对方案的安全性进行了分析。     

基于离散对数问题的（t,n）门了发数字签名方案

本文基于离散对数问题提出了一 个新的（ｔ，ｎ）门限数字签名方案，该方案的一个突出优点是系统中的任何ｔ个成员不能重构系统的秘密密钥。     

Efficient metering schemes with pricing

In order to decide on advertisement fees for Web servers, Naor and Pinkas (see Proc. Advances in Cryptology-EUROCRYPT'98 (Lecture Notes in Computer Science). New York: Springer-Verlag, vol.1403, p.576-590, 1998) introduced metering schemes. They proposed metering schemes in which any server is able to compute a proof to be sent to an audit agency if and only if it has been visited by at least a certain number, say h, of clients. In such schemes, any server which has been visited by less than h clients has no information about the proof; consequently, it does not receive any money from the audit agency. In order to have a more flexible payment system, Blundo, De Bonis, and Masucci (see Proc. 4th Int. Symp. Distributed Computing-2000 (Lecture Notes in Computer Science). New York: Springer-Verlag, vol.1914, p.194-208,2000) introduced metering schemes with pricing. These schemes allow different rates of payments based on the number of visits that each server has received. In this paper, we are interested in the efficiency of metering schemes with pricing. We propose a new model for metering schemes with pricing and we provide lower bounds on the size of the information distributed to clients and servers, and on the number of random bits needed by the audit agency to set up a metering scheme with pricing. These bounds are tight, as we provide a scheme which achieves them with equality. Compared to the scheme presented by Blundo, De Bonis, and Masucci, our scheme distributes less information to clients and servers. The drawback of our scheme is that it requires servers to interact with the audit agency in order to compute their proofs     

基于散列链的云存储资源使用度量机制研究

云存储服务的一种主要收费模式为依据服务提供商度量的客户资源实际使用量进行计费。因此,支付方和服务提供商之间的信任问题成为这种商业计费模式的关键因素,并可能引发安全问题。一方面,云存储服务提供商或者内部人员可能声称更多的客户资源使用量而多收取服务费用;另一方面,支付方可能否认已使用的资源从而减少应支付的费用。提出了一种基于散列链的资源使用度量机制,对不同资源分别产生可验证的证据。对于多数资源,现有云存储计费机制可以依据资源使用总量产生证据,但是考虑到存储量随时间不断波动并且资源的计费不仅与存储量相关还与时间因素相关,因此现有机制不能完全适用。提出的存储资源使用度量机制同时考虑时间和存储量2个因素,利用与计费方式关联的散列链产生证据,实现了原有机制的改进,达到了资源使用的可验证度量目标。     

Ideal secret sharing schemes with multiple secrets

We consider secret sharing schemes which, through an initial issuing of shares to a group of participants, permit a number of different secrets to be protected. Each secret is associated with a (potentially different) access structure and a particular secret can be reconstructed by any group of participants from its associated access structure without the need for further broadcast information. We consider ideal secret sharing schemes in this more general environment. In particular, we classify the collections of access structures that can be combined in such an ideal secret sharing scheme and we provide a general method of construction for such schemes. We also explore the extent to which the results that connect ideal secret sharing schemes to matroids can be appropriately generalized.The work of the second and third authors was supported by the Australian Research Council.     

WiMAX系统中RS-CC级联码的算法研究

保证在高速数据传输的情况下提供可靠的服务质量,信道编码是解决此问题的有效途径。文章重点研究了WiMAX系统中RS-CC级联码的编译码技术,尤其是RS编译码和卷积码的Viterbi算法。     

Clamp-and-Forget: A self-sustainable non-invasive wireless sensor node for smart metering applications

Measuring and managing the power consumption of household appliances, as well as that of industrial machineries, is becoming more and more important to improve the distribution and usage of the electrical energy and to reduce the energy bill. We present the design of a non-invasive wireless current meter which can measure AC current up to $60A_{\mathit{RMS}}$ exploiting a small clamp-on inductive sensor. The novelty of the design is a subsystem consisting of a harvesting circuit designed to extract energy from the same current transducer used for measurements. Experiments have been conducted to validate the approach, to assess the accuracy of the sensing system and deviations due to the energy harvester, and to determine the condition which permits us to achieve the energy neutrality and thus, a self-sustainable smart meter.     

基于二元仿射变换构造强盲签名方案

在广义ElGarnal签名方案的基础上，基于二元仿射变换构造一些新的强盲签名方案，并对这些方案进行了检验和分析。     

RS码短码的软判决方法

RS码是差错控制领域中一种重要的线性分组码,而相对于普通的硬判决来说,软判决译码具有纠错能力强的优势。针对RS码(15,11),提出了使用Chase算法实现非二进制码的软判决译码方法,并通过计算机模拟,给出在AWGN信道中的译码结果。     

A new class of linear codes with two-level structure

The binary extended Golay code has a two-level structure, which can be used in the decoding of the code. However, such structure is not limited to the Golay code, in fact, several binary linear codes can be constructed by a projective method which is related to the structure. In this correspondence, the binary (4n,n 2k, ≥min(8, n,2d)) linear codes are resulted from quaternary (n,k,d) linear block codes. Based on the structure, the efficient maximum likelihood decoding algorithms can be presented correspondingly for the derived codes.     

迭代译码的级联Reed-Solomon乘积码与卷积码

该文提出用Reed Solomon(RS)乘积码作为外码,卷积码作为内码的级联码方案并且内外码间用Congruential向量生成的交织图案对RS码符号进行重排列。对此级联码采用的迭代译码基于成员码的软译码算法。当迭代次数达到最大后,通过计算RS码的校正子,提出一种纠正残余错误的方法,进一步提高了系统的误比特性能。仿真结果表明,在AWGN信道中与迭代译码的级联RS/卷积码相比,当误比特率为1e-5时,新系统的编码增益大约有0.4 dB。     

A distributed pricing algorithm for achieving network‐wide proportional fairness

Proportional fairness (PF) scheduling achieves a balanced tradeoff between throughput and fairness and has attracted great attention recently. However, most previous work on PF only considers the single cell scenario. This paper focuses on the problem of achieving network‐wide PF in a generalized multiple base station multiple user network. The problem is formulated as a maximization model and solved using the dual method. By decomposing the dual objective function, we get a distributed pricing based algorithm. Optimality of this algorithm is presented. Although the algorithm is derived using fixed link rate assumption, it can still apply in the presence of time‐varying rates. The proposed algorithm is suitable for distributed systems in the sense that it does not need any inter base station communication at all. Simulations illustrate that the proposed distributed network‐wide PF scheduling algorithm achieves almost the same performance as the centralized one. Compared with traditional local PF (LPF) scheduling, the network‐wide PF scheduling achieves higher throughput, lower throughput oscillation, and greater fairness. Copyright © 2010 John Wiley & Sons, Ltd.