Cross-Layer Encryption of CFB-AES-TURBO for Advanced Satellite Data Transmission Security

As the advanced satellite network can provide extremely diverse data to various types of users, it is of vital importance to achieve data security using encryption over satellite channels. However, since the avalanche effect makes encryption techniques vulnerable to bit errors in the wireless channel, a more powerful encryption technique is required for data confidentiality. In addition, an efficient method for exchanging encryption keys between receivers and transmitters should be capable of managing a large scale of satellites in the network. In this article, we propose a novel superencryption method of joint encryption and channel coding, cipher feedback-advanced encryption standard (CFB-AES)-TURBO, which combines AES in the upper layer and turbo coding as bulk encryption in the physical layer. Because we introduce turbo coding in the CFB mode with AES for each block, our scheme can accomplish dual goals of data protection and bit error correction. We select an encryption block size to maximize throughput based on channel conditions and the security level required for a user, and present a key exchanging solution. We derive processing time gains and analyze computational complexity of the CFB-AES-TURBO. The bit error rate performance improvement with about 12-dB coding gain is achieved. We also enhance the security performance by $10^{15 000}$ times and provide indistinguishability. Finally, we analyze the total expected latency, suggest the minimum key refresh time of geostationary Earth orbit satellites.