支持等式测试的标识加密(identity-based encryption with equality test, IBEET)体制解决了传统等式测试方案中证书管理的问题,得到了广泛的关注.但现有的IBEET体制难以抵抗渗透攻击,且都是基于国外密码算法设计,不具有自主知识产权....支持等式测试的标识加密(identity-based encryption with equality test, IBEET)体制解决了传统等式测试方案中证书管理的问题,得到了广泛的关注.但现有的IBEET体制难以抵抗渗透攻击,且都是基于国外密码算法设计,不具有自主知识产权.基于此,提出一种支持等式测试并具有密码逆向防火墙的SM9标识加密方案(SM9 identity-based encryption scheme with equality test and cryptographic reverse firewalls, SM9-IBEET-CRF).该方案在用户与云服务器的上行信道间部署密码逆向防火墙(cryptographic reverse firewalls,CRF),对用户发出的信息执行重随机化以达到抵抗渗透攻击的作用.该方案拓展国密算法SM9至IBEET领域中,提升其运行效率并丰富国密算法在云计算领域的研究.给出了SM9-IBEET-CRF的形式化定义和安全模型,并在随机预言机模型中考虑2种不同的敌手将此方案在选择密文攻击下的不可区分性与单向性分别形式化地规约到BDH困难假设上.同时,该方案通过考虑第3种敌手证明CRF的部署为其带来维持功能性、保留安全性以及抵抗渗透性.实验仿真和分析结果展示了该方案的有效性.展开更多
This paper develops a Wald statistic for testing the validity of multivariate inequality constraints in linear regression models with spherically symmetric disturbances,and derive the distributions of the test statist...This paper develops a Wald statistic for testing the validity of multivariate inequality constraints in linear regression models with spherically symmetric disturbances,and derive the distributions of the test statistic under null and nonnull hypotheses.The power of the test is then discussed.Numerical evaluations are also carried out to examine the power performances of the test for the case in which errors follow a multivariate student-t(Mt) distribution.展开更多
This paper deals with a coupled system of fourth-order parabolic inequalities ｜u｜t ≥ -△2^u＋｜v｜^q, ｜v｜t ≥-△2v＋｜u｜p^ in S=R^n ×R^＋ withp, q 〉 1, n ≥1. AFujita- Liouville type theorem is establishe...This paper deals with a coupled system of fourth-order parabolic inequalities ｜u｜t ≥ -△2^u＋｜v｜^q, ｜v｜t ≥-△2v＋｜u｜p^ in S=R^n ×R^＋ withp, q 〉 1, n ≥1. AFujita- Liouville type theorem is established that the inequality system does not admit nontrivial nonnegative global solutions on S whenever n/4≤ max（ p＋1/pq-1, q＋1/pq-1 ）. Since the general maximum-comparison principle does not hold for the fourth-order problem, the authors use the test function method to get the global non-existence of nontrivial solutions.展开更多
文摘支持等式测试的标识加密(identity-based encryption with equality test, IBEET)体制解决了传统等式测试方案中证书管理的问题,得到了广泛的关注.但现有的IBEET体制难以抵抗渗透攻击,且都是基于国外密码算法设计,不具有自主知识产权.基于此,提出一种支持等式测试并具有密码逆向防火墙的SM9标识加密方案(SM9 identity-based encryption scheme with equality test and cryptographic reverse firewalls, SM9-IBEET-CRF).该方案在用户与云服务器的上行信道间部署密码逆向防火墙(cryptographic reverse firewalls,CRF),对用户发出的信息执行重随机化以达到抵抗渗透攻击的作用.该方案拓展国密算法SM9至IBEET领域中,提升其运行效率并丰富国密算法在云计算领域的研究.给出了SM9-IBEET-CRF的形式化定义和安全模型,并在随机预言机模型中考虑2种不同的敌手将此方案在选择密文攻击下的不可区分性与单向性分别形式化地规约到BDH困难假设上.同时,该方案通过考虑第3种敌手证明CRF的部署为其带来维持功能性、保留安全性以及抵抗渗透性.实验仿真和分析结果展示了该方案的有效性.
基金supported by the National Natural Science Foundation of China under Grant No.11301514National Bureau of Statistics of China under Grant No.2012LZ012
文摘This paper develops a Wald statistic for testing the validity of multivariate inequality constraints in linear regression models with spherically symmetric disturbances,and derive the distributions of the test statistic under null and nonnull hypotheses.The power of the test is then discussed.Numerical evaluations are also carried out to examine the power performances of the test for the case in which errors follow a multivariate student-t(Mt) distribution.
基金supported by the National Natural Science Foundation of China (Nos. 10771024,11171048)the Fundamental Research Funds for the Central Universities (No. 851011)
文摘This paper deals with a coupled system of fourth-order parabolic inequalities ｜u｜t ≥ -△2^u＋｜v｜^q, ｜v｜t ≥-△2v＋｜u｜p^ in S=R^n ×R^＋ withp, q 〉 1, n ≥1. AFujita- Liouville type theorem is established that the inequality system does not admit nontrivial nonnegative global solutions on S whenever n/4≤ max（ p＋1/pq-1, q＋1/pq-1 ）. Since the general maximum-comparison principle does not hold for the fourth-order problem, the authors use the test function method to get the global non-existence of nontrivial solutions.
