A new efficient physical layer OFDM encryption scheme

In this paper, we propose a new encryption scheme for OFDM systems. The reason for physical layer approach is that it has the least impact on the system and is the fastest among all layers. This scheme is computationally secure against the adversary. It requires less key streams compared with other approaches. The idea comes from the importance of orthogonality in OFDM symbols. Destroying the orthogonality create intercarrier interferences. This in turn cause higher bit and symbol decoding error rate. The encryption is performed on the time domain OFDM symbols, which is equivalent to performing nonlinear masking in the frequency domain. Various attacks are explored in this paper. These include known plaintext and ciphertext attack, frequency domain attack, time domain attack, statistical attack and random guessing attack. We show our scheme is resistant against these attacks. Finally, simulations are conducted to compare the new scheme with the conventional cipher encryption.