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The expansion of information technology infrastructure is encountered with Advanced Persistent Threats (APTs), which can launch data destruction, disclosure, modification, and/or Denial of Service ...

Co-residency of different tenants’ virtual machines (VMs) in cloud provides a good chance for side-channel attacks, which results in information leakage. However, most of current defense suffers from the generality or compatibility problem, thus failing in immediate real-world deployment. VM migration, an inherit mechanism of cloud systems, envisions a promising countermeasure, which limits co-residency by moving VMs between servers. Therefore, we first set up a unified practical adversary model, where the attacker focuses on effective side channels. Then we propose Driftor, a new cloud system that contains VMs of a multi-executor structure where only one executor is active to provide service through a proxy, thus reducing possible information leakage. Active state is periodically switched between executors to simulate defensive effect of VM migration. To enhance the defense, real VM migration is enabled at the same time. Instead of solving the migration satisfiability problem with intractable CIRCUIT-SAT, a greedy-like heuristic algorithm is proposed to search for a viable solution by gradually expanding an initial has-to-migrate set of VMs. Experimental results show that Driftor can not only defend against practical fast side-channel attack, but also bring about reasonable impacts on real-world cloud applications.

In order to deal with the rapid growth of mobile data traffic and reduce the infrastructure capital expenditure (CAPEX) and operating expense (OPEX), C-RAN is introduced into wireless access network architecture. C-RAN can implement the separation of baseband processing unit (BBU) and remote radio head (RRH). Baseband processing resources are shared by the centralizing deployment of BBU in data center, while RRH is only as a wireless access point that is responsible for sending and receiving signals. Software Defined Network (SDN) and Network Function Virtualization (NFV), the candidate technologies for future development of wireless access network, can promote the virtualization of wireless access network. In this paper, the dynamic allocation of carrier resource in BBU pool is studied, and a dynamic combination allocation algorithm based on Karnaugh map and enhance genetic algorithm (KMEG) for resource allocation of carrier resource is also presented. The simulation results show that this algorithm can deal with different mobile service request for underlying resource effectively, which can adjust system capacity dynamically on demand and achieve the dynamic share of heterogeneous underlying resources in BBU pool. In addition, this algorithm can improve the receiving rate of VNs compared with the static resource allocation algorithm, which can enhance the utilization rate of underlying resources and spectrum efficiency greatly.