  We suggest secure Vehicle-to-Vehicle communications in a secure cluster.
Here, the security cluster refers to a group of vehicles having a certain level
or more of secrecy capacity. Usually, there are many difficulties in defining
secrecy capacity, but we define vehicular secrecy capacity for the vehicle
defined only by SNR values. Defined vehicular secrecy capacity is practical and
efficient in achieving physical layer security in V2V. Typically, secrecy
capacity may be changed by antenna related parameters, path related parameters,
and noise related parameters. In addition to these conventional parameters, we
address unique vehicle-related parameters, such as vehicle speed, safety
distance, speed limit, response time, etc. in connection with autonomous
driving. We confirm the relationship between vehicle-related secrecy parameters
and secrecy capacity through modeling in highway and urban traffic situations.
These vehicular secrecy parameters enable real-time control of vehicle secrecy
capacity of V2V communications. We can use vehicular secrecy capacity to
achieve secure vehicle communications from attackers such as quantum computers.
Our research enables economic, effective and efficient physical layer security
in autonomous driving.
