A Novel Physical Layer Encryption Algorithm Based on Statistical Characteristics of Time-Selective Channels

Currently, the security of information in the physical layer has attracted much attentions. However, such a physical layer security of conventional study depends on the assumption of reciprocity between the uplink and downlink channels. This assumption cannot be ensured in the time-selective channel of mobile communications. Hence, this paper proposes an encryption algorithm in mobile communications. First, the statistics of time-selective channel are extracted to act as the seeds for multiple chaos generator. Second, the produced chaos sequences are combined to produce the secret code. Finally, the physical signal is encrypted by the simple scrambling operation. We verify the proposed algorithm by computer simulations, and the results demonstrate that the encrypted data can be successfully recovered by the legal receiver, while the sniffer produces poor and flat bit-error-rate performance in a wide range of signal-to-noise ratios.