Physical Layer Secret Key Capacity of Two Moving Terminals

When extracting secret key from shared wireless channel between two legitimate moving terminals, its capacity is affected by the time difference of channel sampling, terminal's mobility, and additive noise. In order to quantitatively analyze their effects, a closed-form solution to physical layer secret key capacity in the time domain is derived over the uniform scattering environment. Afterwards, simulations in the uniform and non-uniform scattering environment are carried out to demonstrate its validity and applicability, respectively. Simula-tion results show that the derivation can be utilized to provide theoretical reference for physical layer secret key extraction between two moving terminals located among dense scatters.