Cooperative Jamming-Based Physical-Layer Group Secret and Private Key Generation

TL;DR

This paper introduces a secure method for generating group secret and private keys in wireless relay networks using cooperative jamming.

Contribution

The novel contribution is a cooperative jamming-based scheme for secure group key generation in star-topology wireless networks.

Findings

A cooperative jamming scheme enhances security during channel measurement in wireless relay networks.

The derived SK/PK capacity bounds show minimal difference in high SNR regimes.

Simulations confirm the proposed scheme's effectiveness in ensuring secure and efficient group key generation.

Abstract

This paper explores physical layer group key generation in wireless relay networks with a star topology. In this setup, the relay node plays the role of either a trusted or untrusted central node, while one legitimate node (Alice) acts as the reference node. The channel between the relay and Alice serves as the reference channel. To enhance security during the channel measurement stage, a cooperative jamming-based scheme is proposed in this paper. This scheme allows the relay to obtain superimposed channel observations from both the reference channel and other relay channels. Then, a public discussion is utilized to enable all nodes to obtain estimates of the reference channel. Subsequently, the legitimate nodes can agree on a secret key (SK) that remains secret from the eavesdropper (Eve), or a private key (PK) that needs to be secret from both the relay and Eve. This paper also derives the lower and upper bounds of the SK/PK capacity. Notably, it demonstrates that there exists only a small constant difference between the SK/PK upper and lower bounds in the high signal-to-noise ratio (SNR) regime. Simulation results confirm the effectiveness of the proposed scheme for ensuring security and efficiency of group key generation.

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