Securing the MIMO Wiretap Channel with Polar Codes and Encryption

TL;DR

This paper proposes a hybrid polar coding and encryption protocol for secure MIMO wiretap channels, introducing a novel key generation method that enhances security without requiring separate key exchange.

Contribution

It introduces a new secure transmission protocol for MIMO channels using polar codes and encryption, including a novel key generation technique that renews keys each transmission.

Findings

Proves weak and strong security conditions for the protocol.

Provides a practical method for computational security.

Demonstrates effectiveness through theoretical security proofs.

Abstract

Polar codes have been proven to be capacity achieving for any binary-input discrete memoryless channel, while at the same time they can reassure secure and reliable transmission over the single-input single-output wireless channel. However, the use of polar codes to secure multiple-antenna transmission and reception has not yet been reported in the open literature. In this paper, we assume a multiple-input multiple-output wiretap channel, where the legitimate receiver and the eavesdropper are equipped with the same number of antennas. We introduce a protocol that exploits the properties of both physical and media access control layer security by employing polar coding and encryption techniques in a hybrid manner in order to guarantee secure transmission. A novel security technique is also proposed, where a cryptographic key is generated based on the information transmitted and renewed every transmission block without the need for a separate key exchange method. Finally, to illustrate the effectiveness of the proposed protocol, we prove the weak and strong security conditions, and we provide a practical method to achieve computational security for the cases where these conditions cannot be established.