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
Internal gravity waves(IGWs)are critical in driving Martian atmospheric motion and phenomena.This study investigates Martian IGWs by using high-resolution data from China’s Tianwen-1 mission and the National Aeronaut...Internal gravity waves(IGWs)are critical in driving Martian atmospheric motion and phenomena.This study investigates Martian IGWs by using high-resolution data from China’s Tianwen-1 mission and the National Aeronautics and Space Administration’s Mars Global Surveyor(MGS)by the radio occultation(RO)technique.Key IGW parameters,such as vertical and horizontal wavelengths,intrinsic frequency,and energy density,are extracted based on vertical temperature profiles from the Martian surface to~50 km altitude.Data reveal that the Martian IGWs are predominantly small-scale waves,with vertical wavelengths between 6 and 13 km and horizontal wavelengths extending to thousands of kilometers.These waves propagate almost vertically and exhibit low intrinsic frequencies close to the inertial frequency,with the characteristic of low-frequency inertial IGWs.Tianwen-1 data indicate stronger IGW activity,higher energy density,and less dissipation than MGS data in the northern hemisphere.Moreover,MGS data in the southern hemisphere show higher buoyancy frequencies and lower vertical wavelengths,suggesting more stable atmospheric conditions conducive to IGW propagation.These extracted IGW characteristics can enhance our understanding of the atmospheric dynamics on Mars and contribute valuable information for parameterization in global circulation models.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National Natural Science Foundation of China(Grant Nos.42174192,12241101,and 91952111).
文摘Internal gravity waves(IGWs)are critical in driving Martian atmospheric motion and phenomena.This study investigates Martian IGWs by using high-resolution data from China’s Tianwen-1 mission and the National Aeronautics and Space Administration’s Mars Global Surveyor(MGS)by the radio occultation(RO)technique.Key IGW parameters,such as vertical and horizontal wavelengths,intrinsic frequency,and energy density,are extracted based on vertical temperature profiles from the Martian surface to~50 km altitude.Data reveal that the Martian IGWs are predominantly small-scale waves,with vertical wavelengths between 6 and 13 km and horizontal wavelengths extending to thousands of kilometers.These waves propagate almost vertically and exhibit low intrinsic frequencies close to the inertial frequency,with the characteristic of low-frequency inertial IGWs.Tianwen-1 data indicate stronger IGW activity,higher energy density,and less dissipation than MGS data in the northern hemisphere.Moreover,MGS data in the southern hemisphere show higher buoyancy frequencies and lower vertical wavelengths,suggesting more stable atmospheric conditions conducive to IGW propagation.These extracted IGW characteristics can enhance our understanding of the atmospheric dynamics on Mars and contribute valuable information for parameterization in global circulation models.
