Abstract: Since the computational complexity of public key cryptography is high, and Power Delay Profile (PDP) model is limited by the distance between the attacker and the user, a wireless communication security strategy based on Differential Flag Byte (DFB) was proposed in the identification and defense of impersonation attack. Meanwhile, the equation to generate the DFB was given. The strategy utilized the transmission data information to generate the DFB equation, establishing the correlation that current flag byte of transmission data frame was determined by the relevant parameter of last frame. Finally, receiving terminal identified attack by testing and verifying the DFB received from the data frame with threshold decision. Through theoretical analysis, DFB could prevent recurrent impersonation attack, when the attacker knew the communicational parameter. Meanwhile, the attacker's effective attack time was shorter, and the attack cycle was longer. And the attacker was limited to a finite ellipse in space. Simulation analysis was carried out with a simple DFB at the end. The results show that wireless communication based on the simple DFB strategy can identify and defense impersonation attack by setting the appropriate threshold, when the communication system's Signal-to-Noise Ratio (SNR) was above -4 dB.

Key words: impersonation attack, wireless communication security, Point-to-Point Protocol (PPP), threshold decision, attack recognition

摘要： 针对公共密钥密码系统识别模拟攻击的计算复杂度高,而功率时延模型(PDP)又受限于模型必须存在足够距离差的问题,提出一种基于差分标志字节(DFB)的无线通信安全策略,并给出了生成DFB的差分方程。该策略利用用户传输的数据信息,建立适当的差分标致字节的生成方程,使得当前传输的数据帧的标志字节由已传帧的相关参数决定,最后接收端通过阈值判决验证接收数据帧的差分标致字节,识别模拟攻击。通过理论分析,差分标致字节可以防止攻击者利用已掌握的部分通信参数信息,对用户实施反复的模拟攻击。在时间上,攻击者有效攻击时间更短,攻击达成周期更长。在空间上,攻击者空间位置被限制在有限椭圆内。最后,结合一种具体、简易的DFB进行了仿真分析,结果表明,此种简易模型下,通信系统的信噪比(SNR)高于-4 dB时,系统能够通过设置合适的阈值,能够实现针对模拟攻击的识别与防护。

关键词: 模拟攻击, 无线通信安全, 点对点协议, 阈值判决, 攻击识别