A simple location-dependent key generation method based on multiple antennas for securing wireless communication

Security is an important issue in wireless communication systems as the wireless channel is unguided. Cryptographic techniques in the wired communication may be used to secure the wireless communication, but the characteristics of radio channel are not exploited efficiently. This paper proposes a simple key generation method for securing wireless communication. It assumes that each terminal is equipped with multiple antennas; the method measures the special location relation between legitimate parties exploiting the technique of time difference of arrival. On the basis of the reciprocity principle, the result obtained by the two parties is identical; hence the same location-dependent key is separately generated. Since the completely identical result is impossible in practice due to the presence of noise and interference, a robust quantization technique is hence used. Simulation results show that the proposed method is effective to generate different keys in different locations and thus guarantees the wireless communication security.