Self-Sustainable Key Generation: Strategies and Performance Bounds under DoS Attacks

TL;DR

This paper introduces a self-sustainable wireless key generation method resilient to DoS attacks by using frequency hopping and resource allocation, ensuring secure key exchange without prior credentials.

Contribution

It proposes a novel frequency-hopping based key generation scheme that evades reactive jamming attacks and provides practical resource allocation solutions for maximizing secret bits.

Findings

Frequency hopping effectively evades reactive jamming.

Resource allocation optimizes secret key bits extraction.

Practical low-complexity solutions are feasible.

Abstract

Denial-of-Service (DoS) threats pose a major challenge to the idea of physical-layer key generation as the underlying wireless channels for key extraction are usually public. Identifying this vulnerability, we study the effect of DoS threats on relay-assisted key generation, and show that a reactive jamming attack on the distribution phase of relay-assisted key generation can forbid the nodes from extracting secret keys. To circumvent this problem, we propose a self-sustainable key generation model, wherein a frequency-hopping based distribution phase is employed to evade the jamming attack even though the participating nodes do not share prior credentials. A salient feature of the idea is to carve out a few bits from the key generation phase and subsequently use them to pick a frequency band at random for the broadcast phase. Interesting resource-allocation problems are formulated on how to extract maximum number of secret bits while also being able to evade the jamming attack with high probability. Tractable low-complexity solutions are also provided to the resource-allocation problems, along with insights on the feasibility of their implementation in practice.