云存储服务在以其低成本、高扩展等优势获得广泛青睐的同时,也为实现信息资产安全与隐私保护带来了极大的冲击与挑战.目前,安全已成为云存储服务亟待解决的重要问题.提出了一种可信的云存储控制模型(Trusted Control Model of CloudStorage,TCMCS).TCMCS通过密文访问控制及完整性验证对用户数据进行预处理来保证数据的机密性与完整性;引入可信第三方存储密钥信息,以实现安全、可靠的数据共享;借鉴中间件的设计思想以屏蔽不同云存储平台之间的差异以及分离数据操作过程中的安全操作与业务逻辑.基于安全的多方计算理论,证明了TCMCS的安全性.仿真实验表明,TCMCS在不降低云存储服务平台数据操作性能的基础上,保证了数据的安全性.
Free riding has a great influence on the expandability,robustness and availability of Peer-to-Peer(P2P) network.Controlling free riding has become a hot research issue both in academic and industrial communities.An incentive scheme is proposed to overcoming free riding in P2P network in this paper.According to the behavior and function of nodes,the P2P network is abstracted to be a Distributed and Monitoring-based Hierarchical Structure Mechanism(DMHSM) model.A utility function based on several influencing factors is defined to determine the contribution of peers to the whole system.This paper also introduces reputation and permit mechanism into the scheme to guarantee the Quality of Service(QoS) and to reward or punish peers in the network.Finally,the simulation results verify the effectiveness and feasibility of this model.
