The analysis of a novel secure MIMO communication system

This paper deeply analyzes the security of encrypting algorithm for a novel secure multi-input multi-output (MIMO) communication system based on time varying linear transformation (TVLT). In our previous papers, a new encrypting mechanism for MIMO system was proposed. Without exhaustive checks for proper space-time codes, a coded MIMO system can simply achieve full diversity through TVLT. Further, utilizing the special property of TVLT, a new encrypting mechanism was given consequently. In this paper, the novel encrypting algorithm is improved, the security of the algorithm is studied carefully and corresponding temporal complexity of attack is discussed in detail. The high reliability of new system is proved. Compared with the common encrypting methods for MIMO system, new mechanism accomplishes both TVLT and encrypting process for space-time codewords together, it almost has no effect on the transmit data rate. The simulation results also verified the validity and performance of the new encrypting method.