A study of secure communication with secret sharing method in MIMO eigen stream parallel channels

This letter proposes a secure transmission method using spatially parallel channels formed in a multi-input multi-output (MIMO) communication scenario. In the proposed method, the transmitted information is divided into pieces using a secret-sharing method. These generated pieces are then transmitted separately to the destination through the parallel sub-channels of the MIMO communication link. The secret-sharing method ensures that the transmitted information remains unrevealed unless all the divided pieces are obtained, thus achieving secure communication by establishing an advantageous situation for the legitimate receiver to gather the divided pieces against wiretappers in the surrounding area. Computer simulations demonstrate that allocating transmission power inverse-proportionally to the channel gains among the MIMO sub-channels creates a secure link to the receiver from the channel capacity perspective. The secret capacity of the link increases with the number of antenna elements in the MIMO configuration at the expense of power gain.