A Man-in-the-Middle (MiM) can collect over-the-air packets whether from a mobile or a base station, process them, possibly modify them, and forward them to the intended receiver. This paper exhibits the REVEAL protocol that can detect a MiM, whether it has half duplex capability, full duplex capability, or double full duplex capability. Protocol is based on synchronizing clocks between the mobile and the base station, with the MiM being detected if it interferes in the synchronization process. Once synchronized, the REVEAL protocol creates a sequence of challenge packets where the transmission times of the packets, their durations, and their frequencies, are chosen to create conflicts at the MiM, and make it impossible for the MiM to function. We implement the REVEAL protocol for detecting a MiM in 4G technology. We instantiate a MiM between the 4G/5G base station and a mobile, and exhibit the successful detection mechanisms. With the shared source code, our work can be reproduced using open software defined cellular networks with off-the-shelf devices

翻译：中间人（MiM）可以截获空中传输的数据包（无论是来自移动终端还是基站），对其进行处理（可能包括修改），然后转发给预期的接收方。本文提出了REVEAL协议，该协议能够检测具有半双工、全双工或双全双工能力的中间人。该协议基于移动终端与基站之间的时钟同步，若中间人干扰同步过程则会被检测到。一旦完成同步，REVEAL协议会生成一系列挑战数据包，通过精心选择这些数据包的传输时间、持续时间和工作频率，在中间人处制造冲突，使其无法正常工作。我们基于4G技术实现了REVEAL协议用于检测中间人。在4G/5G基站与移动终端之间实例化了一个中间人，并成功展示了检测机制。通过共享的源代码，我们的工作可利用现成的软件定义蜂窝网络设备进行复现。