Cyber Times International Journal of Technology & Management

With the advancement in wireless technology, people and organizations have become highly dependent on wireless form of communication. More and more wireless applications are emerging that require transmission of private data, such as Net-banking via a wireless access point and mobile payments using device-to-device link. It is highly essential to prevent this private data from eavesdropping attacks, which becomes difficult in a wireless channel due to it's broadcast nature. Even though the existing cryptographic techniques have improved significantly to ensure a secure communication, there are still many issues associated with them which has resulted in the introduction of a new security paradigm for wireless networks, called Physical Layer Security. Various Physical Layer Security methods have been devised for secret key generation and distribution, by exploiting the wireless channel randomness and dynamics. However, very low secret key generation rates are obtained if the rate at which the channel changes is not fast. In this paper, a novel Physical Layer Security method using OFDM has been devised to securely exchange a secret key between a sender and a receiver. The devised method is independent of channel variations and hence faster. Finally, the devised method has been validated by calculating Bit Error Rate at the receiver and the eavesdropper using simulation results in MATLAB.