On Design of Covert Communication System with Frequency Hopping by OFDM

With the rapid development of computer networks, network information security has gradually been concerned. The research on covert channel has become one of a hot issue in information security. However, the secure communication with encryption may attract much attention of the adversaries due to the random cipher messages. Therefore, the covert communication technology becomes a hot issue, since the covert communication can escape the monitor of the manicous users. In this paper, we have proposed a novel covert communication system by using frequency modulation to transmit covert information. With the of orthogonal frequency division multiplexing (OFDM) scheme, we propose to embedded the covert bits with frequency hopping. Furthermore, in the covert communication system, we put forth that the frequency of random jitter is employed as the carrier of covert messages, and the spread spectrum is encoded to encrypt the covert information. Simulation results show that the proposed covert communication system can achieve a good performance on bit error ratio and reliable covert communication.