A system that is capable of detecting a Man in the Middle attack is disclosed. The system includes a receive circuit for receiving incoming packets. The system also includes a digitized model of at least part of the receive circuit and optionally part of the transmit circuit. The system compares the output from the digitized model with the output from the read circuit to determine the likelihood of a Man in the Middle Attack. In certain embodiments, the digitized model is a finite impulse response filter with multiple taps. The system correctly identifies Man in the Middle attacks more than 90% of the time when the signal to noise ratio is greater than 20 dB.