一个适应性安全的支持用户私钥撤销的KP-ABE方案

用户私钥撤销是基于属性的加密(Attribute Based Encryption,ABE)方案在实际应用中所必需解决的问题.现有的支持用户私钥撤销的ABE方案通过引入用户身份的概念,以撤销用户身份的方式实现了对用户私钥的撤销,但其安全性只能达到选择性安全.本文借鉴已有方案的思想,通过将Lewko等人提出的适应性安全ABE方案与Leyou Zhang提出的适应性安全基于身份的组播加密方案相结合,利用双系统加密技术,在合数阶双线性群上实现了一个适应性安全的支持对用户私钥进行撤销的KP-ABE方案.

SM9用户私钥在线分发技术

SM9密码算法属于基于标识的密码(Identity Based Crytograph,IBC)体系,它利用用户终端的标识替代或将其演化为公钥,无须公钥证书授权(Certificate Authority,CA),降低了密钥资源管理和部署难度,适用于有较高安全需求的物联网应用场景。但用户私钥分发需将用户终端集中于密钥管理系统并以离线方式写入用户终端的密码载体,不能通过网络在线方式写入,因此存在工作量大、管理效率低的不足。基于SM9密钥管理技术体制,通过相关安全性设计,提出了一种用户私钥在线分发方法,可有效推进SM9在物联网领域的应用。

一种新的网站用户登录验证方案

由于计算机网络的开放性导致其中存在许多的安全漏洞和安全威胁,网络中的各类资源很容易被人非法访问和下载。因此对网络资源访问者的合法身份进行验证就显得非常重要。对目前互联网上各种网站采用的"用户名+用户密码+图片验证"登录验证方式进行了分析,针对其存在的缺陷,提出了一种"用户名+用户密码+用户私钥+图片验证"登录验证方案,并对其每一个子模块及特点进行了详细的论述。该方案增强了网站用户登录系统的安全性。

基于代理重加密的财务数据安全共享技术

为保证财务数据的机密性,提出基于代理重加密的财务数据安全共享技术。建立用户私钥,分别利用对称加密与属性加密混合方法获得密钥密文与数据密文,生成新的访问结构并获取重加密密文;分析云储存结构,将云储存结构分为接入、接口、管理和储存四个层次,定义云端储存设备、信息属主与请求用户三个角色的基本职责,设置领导与群众节点构建数据储存模型,通过Raft协议集群内部实现节点的储存与传输;创新性地设计共享合约机制,确认签名信息,发布储存与共享交易信息,经过权限校对与安全检测,实现信息安全共享。实验结果表明,所提技术加密和解密时间均低于100 s,数据被破解数量仅为8个,能够降低数据特征显著度,减少被破解次数,为信息共享提供可靠保障。

A Generic Construction of Ciphertext-Policy Attribute- Based Encryption Supporting Attribute Revocation

Attribute-based encryption is drawing more attention with its inherent attractive properties which are potential to be widely used in the newly developing cloud computing. However, one of the main obstacles for its application is how to revoke the attributes of the users, though some ABE schemes have realized revocation, they mostly focused on the user revocation that revokes the user＇s whole attributes, or attribute revocation under the indirect revocation model such that all the users＇ private keys will be affected by the revocation. In this paper, we define the model of CP-ABE supporting the attribute revocation under the direct revocation model, in which the revocation list is embed in the ciphertext and none of the users＇ private keys will be affected by the revocation process. Then we propose a generic construction, and prove its security with the decision q-BDHE assumption.

Adaptively Secure Attribute-Based Encryption Supporting Attribute Revocation

Attribute revocation is inevitable and al- so important for Attribute-Based Encryption （ABE） in practice. However, little attention has been paid to this issue, and it retrains one of the rmin obsta-cles for the application of ABE. Most of existing ABE schemes support attribute revocation work under indirect revocation model such that all the users＇ private keys will be affected when the revo-cation events occur. Though some ABE schemes have realized revocation under direct revocation model such that the revocation list is embedded in the ciphertext and none of the users＇ private keys will be affected by revocation, they mostly focused on the user revocation that revokes the user＇s whole attributes, or they can only be proven to be selectively secure. In this paper, we first define a model of adaptively secure ABE supporting the at- tribute revocation under direct revocation model. Then we propose a Key-Policy ABE （KP-ABE） scheme and a Ciphertext-Policy ABE （CP-ABE） scheme on composite order bilinear groups. Finally, we prove our schemes to be adaptively secure by employing the methodology of dual system eno cryption.

消除重复数据的加密云存储系统

0引言云计算[1]是近几年最热门的互联网技术,同时也是发展最为迅速的互联网服务模式。随着云计算重心的迁移以及大数据的兴起,存储即服务（Storage-as-a-Service,SaaS）作为云计算的支撑技术迅速发展,同时单独的云存储服务（cloud storage）在商业上也得到广泛的应用,比如DropB ox、Google Drive等。云存储服务的推广,业界很快发现围绕个人数据的可用性和安全性是云存储服务推广的最大障碍。