  Ensuring the physical layer security (PHY-security) of millimeter wave
(mmWave) communications is one of the key factors for the success of 5G. Recent
field measurements show that conventional fading models cannot accurately model
the random fluctuations of mmWave signals. To tackle this challenge, the
fluctuating two-ray (FTR) fading model has been proposed. In this
correspondence, we comprehensively analyze the PHY-security in mmWave
communications over FTR fading channels. More specifically, we derive
analytical expressions for significant PHY-security metrics, such as average
secrecy capacity, secrecy outage probability, and the probability of strictly
positive secrecy capacity, with simple functions. The effect of channel
parameters on the PHY-security has been validated by numerical results.
