Network-Centric Countermeasures Against Integrated Sensing Enabled Jamming Adversaries

TL;DR

The paper addresses ISAJ-era security in ISAC networks by evaluating Kerckhoffs'-principle-compliant countermeasures. It introduces the Network-Centric Mitigation Strategy (NCMS), which recruits network-assisted users to cooperatively transmit while leveraging a shared secret-key for reliable and covert communication, and it analyzes both error performance and entropy-based security. The work derives decoding strategies (including a Disjoint Decoder) and upper bounds on decoding error, and demonstrates how increasing the number of mimicry groups $L_C$ enhances adversary uncertainty via the normalised entropy $H_{norm}$ at the cost of some reliability. An optimization framework balances reliability and covertness through the energy-splitting parameter $ ext{α}$ (or $eta$) and $L_C$, with simulation results validating the trade-offs and revealing how network size and SNR influence the outcomes. Overall, the NCMS provides a practical, Kerckhoffs'-principle-aligned approach to secure and covert communication against ISAJ adversaries in multi-band wireless networks, highlighting key overheads and future research directions.

Abstract

Recent developments in Integrated Sensing and Communication have led to new adversarial models in wireless security through Integrated Sensing and Jamming (ISAJ) adversaries. ISAJ adversaries, owing to their sensing capabilities, are known to inject jamming energy over the victim's frequency band, and also use generalized energy measurements on various network frequencies to detect the presence of countermeasures. Existing countermeasures against such ISAJ adversaries are laid under the assumption that the adversary does not have the knowledge of the countermeasure. However, according to Kerchoffs' principle in cryptography, security of a countermeasure should only rely on the secret-keys, not on the obfuscation of the countermeasure. On testing the security of existing countermeasures, we observe that they violate Kerchoffs' principle, thus motivating the need for new countermeasures. In this regard, we propose a novel network-centric countermeasure against ISAJ adversaries, wherein a group of users in the network assist the victim to reliably communicate her messages in a covert manner. Firstly, we analyse the error performance of the proposed countermeasure, and study its behavior on the number of assisting users in the network. Subsequently, to validate its security against Kerchoffs' principle, we study the Shannon's entropy associated with the presence of the victim's messages in the network and analyse its behaviour as a function of the number of assisting users. Finally, to study the interplay between reliability and covertness, we pose interesting optimization problems and solve them to choose the underlying parameters of the countermeasure and the number of assisting users.

Figures (6)

• Figure 1: Depiction of the network model, wherein Alice and the rest of the $L-1$ network users communicate with Bob, over their allocated uplink frequencies. In this network, the ISAJ adversary, namely Dave, injects jamming energy over Alice's frequency band, while monitoring different network frequencies to detect countermeasures.
• Figure 2: The frame structure of information symbols over (a) the $f_{CB}$ band, and (b) over the $f_{HB}$ and the $f_{TB}$ bands.
• Figure 3: Plots depicting $Pe$ and $Pe_{th}$, as a function of $\alpha$, for $L_C=10$, $N_C=4$, and at an SNR of $35$ dB. We observe that the minima of $Pe$ and $Pe_{th}$, are around the same value of $\alpha$.
• Figure 4: Plot depicting $Pe$ as a function of SNR, for different values of $L_C$ and $L=42$. From these plots, we observe that as $L_C$ increases, $Pe$ increases.
• Figure 5: Figure shows the plot of normalised entropy as a function of SNR, for different values of $L_C$ and $L=42$. From these plots, we observe that as $L_C$ increases, the normalised entropy increases.

Theorems & Definitions (1)

• Theorem 1