Universally composable proactive threshold RSA signature

Recently some efforts were made towards capturing the security requirements within the composable security framework.This modeling has some significant advantages in designing and analyzing complex systems.The threshold signature was discussed and a definition was given based on the universal composability framework, which is proved to be equivalent to the standard security definition.Furthermore, a simple, effcient and proactive threshold RSA signature protocol was presented.It is proved to be correct, consistent and unforgeable relative to the environment that at most t-1 parties are corrupted in each proactive stage.It is also secure under the universal composability framework.It is a UC based security and is proved to be equivalent to the standard security.     

A universal composability framework for analysis of proxy threshold signature

The universal composability framework is a new approach for designing and analyzing the security of cryptographic protocols. In this framework, the security of protocols is maintained under a general protocol composition operation. In the paper, we propose the universal composability framework for the analysis of proxy threshold signature and present a universally composable secure proxy threshold signature scheme which is the first one in this area. The proposed scheme is suitable for the mobile agents, which should migrate across different environment through network. Furthermore, we give the concrete analysis of the reduction to prove the security of the proposed scheme.     

Simple and efficient password-based authenticated key exchange protocol

Password-based authenticated key exchange (PAKE) protocols are cryptographic primitives which enable two entities, who only share a memorable password, to identify each other and to communicate over a public unreliable network with a secure session key. In this paper, we propose a simple, efficient and provably secure PAKE protocol based on Diffie-Hellman key exchange and cryptographic hash function. Our protocol is secure against dictionary attacks. Its security is proved based on the hardness of the computational Diffie-Hellman problem in the random oracle model.     

Provably Secure Short Proxy Signature Scheme from Bilinear Maps

An enhanced formal model of security for proxy signature schemes is presented and a provably secure short proxy signature scheme is proposed from bilinear maps. The proposed proxy signature scheme is based on two short secure signature schemes. One is used for delegating the signing rights and computing the standard signature; the other is used for computing proxy signature. Finally, a security proof of the proposed proxy signature scheme is showed by reducing tightly the security of the proposed proxy signature scheme to the security of the two basic signature schemes. The proposed proxy signature scheme has the shortest ordinary signatures and proxy signatures. Moreover, the proxy signature generation needs no pairing operation and verification needs just two pairing operation.     

一体化网络中可证明安全的三方认证协议

为了有效地保证终端、接入交换路由器和认证中心的安全,本文提出了一体化网络中可证明安全的三方认证协议．该协议实现了终端和认证中心之间及接入交换路由器和认证中心之间的相互认证,不仅可以有效防止非授权终端接入网络,还可以防止伪造的认证中心和接入交换路由器对终端的欺骗．在BR扩展模型下,可证明该协议是安全的．通过性能分析得出,协议具有很高的效率．     

基于ECC的入侵容忍数字签字方案

入侵容忍是网络安全中的一种新方法,该方法保证系统在遭受攻击的情况下信息的机密性、完整性和可用性.本文基于安全的椭圆曲线,结合门限体制、可验证秘密共享体制以及主动秘密共享方案,给出一种新的入侵容忍签字方案.新方案在签名时可以避免密钥重构,防止了密钥的泄漏.     

一种基于RSA的有序多重数字签名方案

提出了一种基于RSA的有序多重数字签名方案,该方案能够允许多个用户顺序地对一份文件进行签名,最后形成一个群体签名;并提出一种新的签名验证方案,可以有效地防止成员的欺诈行为,因而更具有安全性和实用性.     

A Practical SSL Server Performance Improvement Algorithm Based on Batch RSA Decryption

The secure socket layer/ transport layer security（SSL/TLS） handshake protocol uses public key cryptographic algorithms such as RSA for key establishment. Typically, public key cryptographic algorithm is computational intensive due to the modular multiplications. Therefore, SSL/TLS servers often become swamped while performing public key decryptions when the simultaneous requests increase quickly. A batch RSA decryption algorithm was proposed. The novel algorithm provides the reasonable response time and optimizes server performance significantly. The decryption speedup is proportional to the batch size b, for instance, the speedup factor is 4, while in Shacham＇s scheme the acceleration rate is only 2.5 when b = 4.     

Distributed certificateless key encapsulation mechanism secure against the adaptive adversary

This paper proposes an adaptively secure solution to certificateless distributed key encapsulation mechanism from pairings by using Canetti's adaptive secure key generation scheme based on discrete logarithm. The proposed scheme can withstand adaptive attackers that can choose players for corruption at any time during the run of the protocol, and this kind of attack is powerful and realistic. In contrast, all previously presented threshold certificateless public key cryptosystems are proven secure against the more idealized static adversaries only. They choose and fix the subset of target players before running the protocol. We also prove security of this scheme in the random oracle model.     

一种高效的移动云服务环境下隐私保护认证协议

为了解决移动云服务环境的互相认证和隐私保护问题,设计了一种改进的移动云服务环境下隐私保护认证协议.该协议结合基于身份的签密技术和多服务器认证技术,保证用户只需注册一次,就可以访问多个移动云服务提供者,同时认证过程不需要可信第三方参与;该协议在移动终端未使用计算复杂度高的双线性对运算和映射到域上的hash运算,其计算效率显著提高. 通过理论分析和实验结果可知:该协议与目前已有的同类协议相比,在移动端的计算时间为45.242 s,其计算效率约为已有同类协议的2倍;具有用户匿名和不可追踪等安全性质;能够抵抗错误口令登录、更改攻击.      

基于NTRU公钥算法的安全OSPF协议研究

OSPF是一种典型的链路状态路由协议,是当前局域网中最常用的路由协议之一.文中简要介绍了OSPF协议的网络安全需求,提出了新的安全OSPF路由协议SOSPF,其中使用加密速度更快的公钥加密算法NTRU来实现OSPF协议的数字签名.采用NS-2平台对其进行仿真,并进行性能和安全性分析.     

Cryptanalysis and Improvement of Digital Multisignature Scheme Based on RSA

Introduction Multisignature is a joint signature generated by agroup of signers. The group has a security policy thatrequires a multisignature to be signed by all groupmembers with the knowledge of multiple privatekeys. Digital multisignatures should have…     

A NEW RSA CRYPTOSYSTEM HARDWARE IMPLEMENTATION BASED ON MONTGOMERY‘S ALGORITHM

IntroductionData security is becoming a more and more im-portantissue nowadays with the ever- creasing pop-ularity of electronical communication[1] . The fun-damental security requirements include confiden-tiality,authentication,data integrity,and nonre-pudiation.To provide such security services,mostsystems use public key cryptography. Among thevarious public key cryptography algorithms,theRSA cryptosystem is the bestknown,most versa-tile,and widely used public key cryptosystem to-day.In pu…     

Efficient Protocol-Proving Algorithm Based on Improved Authentication Tests

A new efficient protocol-proving algorithm was proposed for verifying security protocols. This algorithm is based on the improved authentication tests model, which enhances the original model by formalizing the message reply attack. With exact causal dependency relations between messages in this model, the protocol-proving algorithm can avoid the state explosion caused by asynchronous. In order to get the straight proof of security protocols, three authentication theorems are exploited for evaluating the agreement and distinction properties. When the algorithm terminates, it outputs either the proof results or the potential flaws of the security protocol. The experiment shows that the protocol-proving algorithm can detect the type flaw attack on Neuman-Stubblebine protocol, and prove the correctness of NSL protocol by exploring only 10 states.     

DESIGN OF A DIGITAL SIGNATURE SCHEME BASED ON FACTORING AND DISCRETE LOGARITHMS

Objective Focusing on the security problem of authentication and confidentiality in the context of computer networks, a digital signature scheme was proposed based on the public key cryptosystem. Methods Firstly,the course of digital signature based on the public key cryptosystem was given. Then, RSA and ELGamal schemes were described respectively. They were the basis of the proposed scheme. Generalized ELGamal type signature schemes were listed. After comparing with each other, one scheme, whose Signature equation was (m r)x=j s modФ(p) , was adopted in the designing. Results Based on two well-known cryptographic assumptions, the factorization and the discrete logarithms, a digital signature scheme was presented. It must be required that s“ was not equal to p‘q“ in the signing procedure, because attackers could forge the signatures with high probabilities if the discrete logarithms modulo a large prime were solvable. The variable public key “e“ is used instead of the invariable parameter “3“ in Ham‘s signature scheme to enhance the security. One generalized ELGamal type scheme made the proposed scheme escape one multiplicative inverse operation in the signing procedure and one modular exponentiation in the verification procedure.Conclusion The presented scheme obtains the security that Harn‘s scheme was originally claimed. It is secure if the factorization and the discrete logarithms are simultaneously unsolvable.     

Provably secure and efficient proxy signature with untrustworthy proxy signer

Proxy signature has drawn great concerns.However, there still remains a challenge to construct a provably secure and effcient proxy signature scheme.In this paper, we propose an effcient proxy signature scheme based on factoring, and prove that it is secure in the random oracle.Furthermore, we present a new type of proxy signature, called Proxy Signature with Untrustworthy Proxy Signer, and construct a concrete scheme.     

A Distributed Authentication Algorithm Based on GQ Signature for Mobile Ad Hoc Networks

Introduction Mobile ad hoc networks (MANETs) are newinfrastructureless networks without the usual rout-ing infrastructure like fixed routers and routingbackbones. A mobile ad hoc network is a multi-hop temporary self-organizing system compromisedof a group of mobile nodes with radios. MANETshave some special characteristics: self organizing,dynamic topology, limited bandwidth, resourceconstraint nodes, multi-hop routing, vulnerable tosecurity attacks etc. Recently, MANET has beenone of t…     

一种基于网络安全的复合加密算法的研究

加密技术是保护网络安全的主要手段之一.在传统的DES RSA复合加密算法中,DES不仅存在着弱密钥和半弱密钥,而且在代数结构上存在着互补对称性,在一定程度上降低了破解密文的难度.文中提出一种新的复合加密算法TRA,在提高加密强度的前提下,解决以上问题.描述了TRA的模型和加密过程,并通过相关数据对该算法进行测试,分析了该算法的正确性、复杂度、安全性和效率等,并与传统的复合加密算法进行比较.     

Identity-based verifiably committed signature scheme without random oracles

An identity-based verifiably committed signature scheme （IB-VCS） was proposed, which is proved secure in the standard model （i.e., without random oracles）. It enjoys the setup-free property and stand-alone property, both of which make an exchange protocol more practical. The scheme is unconditionally secure against the cheating signer, its security against the cheating verifier is reduced to the computational Diffie-Hellman （CDH） problem in the underlying group, it is secure against the cheating trusted third party if the underlying Paterson Schuldt＇s identity based signature （IBS） scheme is secure, which is proven true based on the CDH assumption in the standard model.     

Proofs of Security for Improved Rabin Signature Scheme

Introduction Digitalsignatureistheelectronicversionof handwrittensignaturefordigitaldocuments.A digitalsignatureschemeallowsasignertotrans-formanarbitrarymessageintoasignedmessage,suchthatanyonecancheckthevalidityofthe signedmessageusingthesigner'spublickey,but onlythesignerisabletoproducesignedmessages.RSAdigitalsignature[1]isaverypopulardigi-talsignaturescheme,whosesecurityisbasedon theRSAassumption:“foragiveny∈Z*n,itis hardtocomputethemodulare-throotxofysuch thatxe=ymodn”.However,howt…