基于分数规划的X2切换密钥管理安全性研究

Security analysis of X2 handover key management based on fractional programming

为了减少X2切换过程遭受去同步攻击导致的用户信息泄露,提出了一种基于分数规划(Fractional Programming, FP)的X2切换密钥更新方案。该方案在传统FP算法的基础上,首先通过离差标准化将暴露数据包数(Number of Exposed Packets, NEP)和信令开销率(Signalling Overhead Rate, SOR)映射在0—1内,消除NEP和SOR的量纲影响,同时考虑最小值和最大值对NEP和SOR的影响;然后通过FP算法确定最优的密钥更新间隔T_(U)和移动管理实体停留时间T_(R)。仿真结果表明,当T_(U)=2s且T_(R,opt)=1s时,改进FP算法比传统FP算法σ减少了0.25左右。在保证X2切换安全的条件下,改进FP算法确定的最优密钥更新间隔和移动管理实体停留时间有更小的暴露数据包和信令开销率。

In order to reduce the disclosure of user information caused by desynchronization attacks in the X2 handover process, this paper proposes a X2 handover key update scheme based on fractional programming(FP). Based on the traditional FP algorithm, this scheme deploys the dispersion normalization to map the number of exposure packets(NEP) and signaling overhead rate(SOR) within 0—1. Thus, the dimensional effects of NEP and SOR are eliminated, and the effects of minimum and maximum values on NEP and SOR are also considered. Then, the FP algorithm is exerted to determine the optimal key update interval T_(U)and the mobile management entity residence interval T_(R). The simulation results show that when T_(U)=2s and T_(R,opt)=1s, σ of the improved FP algorithm is reduced by about 0.25, compared with that of the traditional FP algorithm. Given that X2 handover security is guaranteed, the optimal key update interval and the mobility management entity residence interval determined by the improved FP algorithm have a smaller number of exposed packets and a smaller signaling overhead rate, which can more effectively reduce the user data leakage caused by desynchronization attacks.