Electronic Warfare (EW) scenarios contemplate powerful and stealthy jamming attacks, able to disrupt any competing wireless communication in the target area. Reactive jamming techniques are especially suitable to this aim. Indeed, by first eavesdropping on the whole radio spectrum used for communications, and then timely injecting random noise as soon as a transmission is detected, reactive jamming represents both an effective and hard-to-detect attack tool. In such a challenging EW scenario, all the solutions currently available in the literature to mitigate reactive jamming require either the deployment of specialized hardware, or the modifications of physical layer protocols—the former solution being expensive, and the latter one usually not viable when considering commercially available wireless devices. In this paper we propose BitTransfer, an anti-jamming protocol enabling wireless communications between neighboring devices even under the above-described stringent requirements and powerful attacker model. BitTransfer embeds information bits in radio activity operations, a 0 being represented by the absence of any radio activity, and a 1 by the reception of a (corrupted) packet at the receiver. To demonstrate its applicability to a wide class of commercial wireless devices, BitTransfer has been implemented using a real constrained hardware platform (the Openmote-b), released as freely available and open-source, and tested using the IEEE 802.15.4 communication technology, adopted within the Bluetooth and Zigbee 3.0 protocol stacks. When under attack by a reactive jammer, BitTransfer can transfer a message of 127 Bit in 11.17 seconds, while competing approaches simply fail. Other than being completely tunable, BitTransfer can also enjoy further improvements by simply increasing the transmission rate of the devices. Finally, its detailed design, open-source availability, robustness, and superior performance when compared against competing solutions, make it a solution of choice in challenging EW scenarios, also paving the way to further research along the highlighted directions.

Introduction

Electronic Warfare (EW) scenarios involve a variety of powerful attacks against wired and wireless networks, where attackers use any meaningful tool to disrupt the operation of the communication infrastructure of the competing entities in the target area [1]. The increasing advancements in manufacturing and embedding technologies experienced in the last decade have boosted the effectiveness of EW systems and strategies, especially in the military application domain [2]. EW systems inspect thoroughly the electromagnetic environment in the target area, analyze the communication technologies used by the competing party, and design ad-hoc stealthy methods to shut them down and reduce organization and response capabilities of the contenders [3], [4]. In this context, jamming is still the most powerful and convenient Denial of Service (DoS) attack that can be performed to disrupt wireless communications [5]. By simply deploying a single device emitting noise at high power on the same channel used for ongoing wireless communications, any radio operation is disrupted, independently from the selected communication technology [6]. In addition, the commercial diffusion of low-cost and low-effort Software Defined Radios (SDRs) has further lowered the technological barrier necessary to launch jamming attacks [7]. Between the large number of jamming attacks that can be achieved, Reactive Jamming is the most effective and difficult to detect [8].