动态自适应安全的（k,n）先应秘密共享系统设计

针对目前先应秘密共享系统基于经验方法的安全参数设置问题,本文将安全检测技术与先应秘密共享方案相结合,提出了动态自适应安全的先应秘密共享系统结构和响应方法.利用系统的安全审计日志,在评估移动攻击安全风险的基础上,分析了系统的共享服务器组由起始安全向入侵转移的渐进过程,建立了系统的状态转移模型,给出了系统的安全性定量分析和评估方法.并且,通过比较不同的门限配置、入侵率和安全阈值等参数情况,说明了维持先应秘密共享系统安全性的一般步骤,通过动态调整运行配置,实现系统安全的自适应控制和管理.给出了该方法应用的具体步骤,并验证了其有效性.

Adaptive Security for (k, n) Proactive Secret Sharing Schemes

The proactive secret sharing (PSS)scheme divides the lifetime of a service into a series of interval, where the shares are periodically refreshed. This paper proposes a quantitative approach to evaluate the security of the proactive secret sharing system against the mobile attacks. Due to the difficulty in estimating quantitatively the attack ability, there have been few efforts to analyze the system security. Using the stochastic modeling techniques, we describe the relationship between the attacker behaviors and the security attributes of system. By probabilistic analysis, we estimate the availability of the proactive secret sharing system. As a result, it shows that the availability is significant dependent on the intrusion rate, the threshold and the time period. According to these results, we can maintain the availability by setting theoretically both threshold and time period based on quantitative approach rather than on the empirical knowl- edge.