多策略属性基全同态加密可在多用户环境下同时实现共享数据的细粒度访问控制和不同策略属性基密文的同态计算。针对目前支持多跳多策略的属性基全同态加密方案密文尺寸较大,同态计算效率不高的问题,提出了一个基于LWE(Learning With Error)问题,支持多跳多策略的属性基全同态短密文加密方案。方案可实现对满足不同访问策略的不同属性集密文进行同态计算;且具备完全动态多跳性质,即任何参与方都可以实时、动态地加入到密文运算的过程中,同态运算后输出的密文能够与新加入参与方的密文再次进行同态运算,即使新加入密文所对应属性集不满足已有的访问策略集。与同类方案相比,方案具有更短的密文和更高的同态计算效率,并且密文扩展更容易实现。最后证明了文中方案具有选择属性下的选择明文攻击不可区分性(IND⁃CPA)安全性。
The mobile botnet, developed from the traditional PC-based botnets, has become a practical underlying trend. In this paper, we design a mobile botnet, which exploits a novel command and control （CC） strategy named Push-Styled CC. It utilizes Google cloud messaging （GCM） service as the botnet channel. Compared with traditional botnet, Push-Styled CC avoids direct communications between botmasters and bots, which makes mobile botnets more stealthy and resilient. Since mobile devices users are sensitive to battery power and traffic consumption, Push- Styled botnet also applies adaptive network connection strategy to reduce traffic consumption and cost. To prove the efficacy of our design, we implemented the prototype of Push-Style CC in Android. The experiment results show that botnet traffic can be concealed in legal GCM traffic with low traffic cost.
