抗延迟攻击的WSN时间同步方法

Delay Attack- Resistant Time Synchronization for WSN

为抵抗延迟攻击,保证时间同步安全正常运行,提出WSN安全时间同步算法。算法采用梯度时间同步,同时修正时间率和本地时间,提高同步精度;采用最小二乘估计计算发送时间、时间率估计值,根据发送时间估计值和实际值偏差、时间率估计值和实际值偏差分别设置阈值检测并排除异常同步信息。仿真结果表明:算法具有同步误差小、异常检测率高的特点,且通过异常检测排除异常同步信息后同步误差降低率高,提高了同步精度和同步安全性。

A security time synchronization algorithm is proposed to resist delay attack and ensure safe time synchronization for Wireless Sensor Networks. The gradient clock synchronization mechanism is adopted to improve the synchronization accuracy by correcting both the logical time rate and the local time. The least squares estimation is adopted to estimate both the transmission time and the time rate. The abnormal synchronization information is detected and eliminated by comparing the deviation between the estimated and actual value of the send time with a threshold,and comparing the deviation of estimated and actual value of the time rate with another threshold. NS2 simulations show that the proposed algorithm has advantage with small synchronization error and high detection rate. The accuracy and the security of synchronization are improved due to the high reduction of synchronization deviation for the abnormal synchronization information being eliminated by adopting anomaly detection.