代理多重签名方案的密码分析与修改

对伊丽江等提出的的代理多重签名方案进行了详细的分析，指出该方案是不安全的，不能抵抗公钥替换攻击和合谋攻击，并给出了两个改进的代理多重签名方案。改进后的方案具有不可否认性，不使用安全信道，以及抵抗公钥替换攻击和合谋攻击等优点。     

Z[ω]环上的两类密码体制

本文在Eisenstein环Z[ω]上得到了两类新的密码体制。它们分别是推广的RSA密码体制和自确认密码体制。安全性分别基于环Z[ω]上整数的分解和Z[ω]环上离散对数的计算。     

A Note on Diophantine Equation Ax~4+ 1 = By~2 and Erds'''' Conjecture on Combinatorial Number

oINTRODUCT1ONLetNbethesetofpositiveintegers.LetA,BeNwithgcd(A,B)=l,B>landBissquarefree.Thereweremanypaperscon-cernedwiththeequationAx4+l=By',x,yeN(1)writtenbyLjunggren,Cohn,KeandSun,andtheauthoretc.(seell]).LjunggrenI']provedthatifA=land(l)hassolution(x,y),thenX2+yJB=n',(2)wheren=uo+v,Inisthefundamentalsolu-tionofPell'sequationu2-Bv2=-l,uo=dut,d,u,eN,dissquarefree.Infact,repeatingthemethodof[3]com-pletely,wecanproveTheoremlTheequation(l)hassolution(x,y)ifandonlyiftheequationAu2…     

Convertible Proxy Signcryption Scheme

In 1996, Mambo et al introduced the concept of proxy signature. However, proxy signature can only provide the delegated authenticity and cannot provide confidentiality. Recently, Gamage et al and Chart and Wei proposed different proxy signcryption schemes respectively, which extended the concept of proxy signature.However, only the specified receiver can decrypt and verify the validity of proxy signcryption in their schemes.To protect the receiver‘ s benefit in case of a later dispute, Wu and Hsu proposed a convertible authenticated encryption scheme, which can enable the receiver to convert signature into an ordinary one that can be verified by anyone. Based on Wu and Hsu‘ s scheme and improved Kim‘ s scheme, we propose a convertible proxy signcryption scheme. The security of the proposed scheme is based on the intractability of reversing the one-way hash function and solving the discrete logarithm problem. The proposed scheme can satisfy all properties of strong proxy signature and withstand the public key substitution attack and does not use secure channel. In addition, the proposed scheme can be extended to convertible threshold proxy signcryption scheme.     

前言

网络已经完全渗透于人类社会的各个方面,形成了现代化生活必须依赖的虚拟空间——网络空间.网络空间安全治理体系早巳引起各国的高度重视,目前正进入治理体系变革的关键时期.网络空间安全治理对于维护国家主权与安全、保障国家繁荣与稳定有着重要意义.网络与系统安全是网络空间安全治理的前提,密码学作为保障网络空间安全的核心与支撑技术,在网络空间安全治理中扮演关键角色.探索适应新时期网络空间安全治理需求的网络安全与密码学新理论、新技术是我们面临的重要课题.     

关于指数丢番图方程的Hugh Edgar问题

p~m=q~n 2 m>1, n>1 (1)where p and q are primes, has the solution 3~3=5~2 2.Hall asked a question how many solutions else are there? Later, Hugh Edgar asked another question how many solutions(m,n) does the Diophantine equation p~m-q~n=2~h;m>1,n≥1,(2) have for primes p, q and integer h? In the references at el., Hall's and Hugh Edgar's problems were partly solved. In this paper, we have proved the following results: THEOREM 1. If p=qt~2±4 or q=pt~2±4, then the equation p~m-q~n=4 has no integer solution in which m>1, n>1. THEOREM 2. If(p,q)=(3,5), (5,3), (5,7), (7,5)(mod 8), then Eq.(2) has no integer solution in which h≥2, except that 3~2-5~1=2~2, 5~3-11~2=2~2 and     

关于丢番图方程ax~2+by~2=p~z

0 Introduction Let p be a prime, and let a, b∈Z_(>0), a>b>1 and (a, b)=1. If the equation X~2+abY~2=p~z, (X,Y)=1, Z>0 (1) has an integer solution (X,Y, Z), then there exists a unique integer solution (X_p, Y_p, Z_p,)which satisfies X_p>0, Y_p>0 and Z_p 0) satisfy the equation ax~2+by~2=2~z,z>2 (2) and x|~*a, y|~*b, where symbol x|~*a means that a is divided exactly by each prime factor of x.     

密码学的新发展

随着网络空间竞争与对抗的日益尖锐复杂,安全问题以前所未有的深度与广度向传统领域延伸.随着移动互联网、下一代互联网、物联网、云计算、命名数据网、大数据等为代表的新型网络形态及网络服务的兴起,安全需求方式已经由通信双方都是单用户向至少有一方是多用户的方式转变.论述了涉及“多方”的现代密码学产生的主要特点:1)“端端”单方模式改变为多方模式——由“一对一”的单方通信模式改变为“一对多”、“多对一”、“多对多”的多方通信模式(这里的“多”通常是动态的由访问结构定义的“多”);2)“位置”本地模式改变为异地模式——计算和处理模式由本地位置向异地位置转变,包括外包计算、外包信号处理、外包聚合等.说明云计算、未来网络、大数据等应用模式对现代密码学提出了新的要求,产生了新的密码学原语.在此基础上,详细介绍了这些密码学原语中属性基加密(ABE)的主要进展,重点介绍了可追踪、可撤销、多权威机构等的ABE问题的解决情况.最后,介绍了这些成果的应用,包括ABE密码原语的芯片研制、芯片应用,重点介绍了电子政务敏感信息加密访问控制系统、银行账户信息加密访问控制系统、安全有线电视分发管理系统、安全移动终端服务系统等加密数据访问控制类应用,以及指纹防伪银行卡、指纹防伪护照、指纹防伪加油卡、指纹防伪门禁卡和指纹防伪身份证等证卡票券防伪认证类应用.