Physical layer secret key (PLSK) attracts much research interest in recent years due to its lightweight properties and potential to be used in real internet-of-things (IoT) applications. However, most existing works focus on PLSK generation between pairwise users under passive eavesdropping and lack of design for group key generation especially when active attacks may exist. In this paper, the RObust and LIghtweight Group key generation Against Active Attack (ROLIG3A) scheme is proposed to achieve reliable, efficient, and secure group secret key generation (GSKG) against various malicious attack patterns. In ROLIG3A, adaptive channel listening and dual code channel transmission are designed to avoid legitimate users from jamming signals. Comparing with the exiting GSKG schemes, more proactive countermeasures, back interference cancellation, and ECC-based information sharing are involved to realize the identification and cancellation of malicious attacks. Simulation results show that ROLIG3A has better security performance than the state-of-the-art GSKG schemes in the face of both sabotage attacks and manipulative attacks. In addition, ROLIG3A can provide an acceptable key generation rate and it is reliable even in low signal-to-noise-ratio (SNR) environments.
Physical layer secret key (PLSK) attracts much research interest in recent years due to its lightweight properties and potential to be used in real internet-of-things (IoT) applications. However, most existing works focus on PLSK generation between pairwise users under passive eavesdropping and lack of design for group key generation especially when active attacks may exist. In this paper, the RObust and LIghtweight Group key generation Against Active Attack (ROLIG3A) scheme is proposed to achieve reliable, efficient, and secure group secret key generation (GSKG) against various malicious attack patterns. In ROLIG3A, adaptive channel listening and dual code channel transmission are designed to avoid legitimate users from jamming signals. Comparing with the exiting GSKG schemes, more proactive countermeasures, back interference cancellation, and ECC-based information sharing are involved to realize the identification and cancellation of malicious attacks. Simulation results show that ROLIG3A has better security performance than the state-of-the-art GSKG schemes in the face of both sabotage attacks and manipulative attacks. In addition, ROLIG3A can provide an acceptable key generation rate and it is reliable even in low signal-to-noise-ratio (SNR) environments.
With the increasing demands for sharing confidential information among massive Internet of Things (IoT) devices in 5G and beyond wireless networks, many applications require the common secret key generation for a group of IoT devices. However, most of the existing works on physical layer secret key generation (PLKG) only focus on the pairwise key generation between two users, which is a low efficient and high cost to be extended to the scenarios of group key generation. In this work, we propose a new efficient multiple-input–multiple-output (MIMO) physical layer group secret key generation scheme to reduce the consumption of channel probing and improve the efficiency for group key generation. Different from current schemes, in the proposed scheme, the transmitter randomly generates the group secret key and directly broadcasts the downlink data symbols to the group users. At the receiver end, each group user can efficiently “observe” the common group key through the downlink broadcasting data symbols, while keeping perfect secrecy of the shared group key against eavesdroppers. The performance of reliability, security, and the group key generation rate is fully investigated, which shows the advantages of high efficiency, low consumption, and strong robustness of the proposed scheme. Extensive simulations are conducted to validate the effectiveness of the proposed scheme.
For the future Internet of Things (IoT) with ubiquitous wireless connectivity, the physical layer secret key (PLSK) scheme has been recognized as an effective and lightweight way to achieve secure communications by exploiting the reciprocity of the wireless channel. Compared with channel state information (CSI)-based PLSK generation schemes, received signal strength (RSS)-based schemes are more advantageous in terms of the communication costs and mobility for the IoT applications. However, due to the vulnerability of predictable channel attacks, RSS-based schemes cannot always guarantee perfect security. In this paper, we combine angle of arrival (AoA) and received signal strength (RSS) to generate physical layer secret key (PLSK). In particular, we propose a novel measurement named effective key generation rate (EKGR) to comprehensively and directly evaluate a PLSK scheme. Meanwhile, we further simplify the conventional PLSK generation steps to meet the low-complexity demand of IoT devices. At last, numerical results demonstrate that comparing with RSS-based and AoA-based schemes, our proposed EKGR of the RSS-AoA-based scheme achieves 78% or even 120% performance improvement.
Physical layer security (PLS) has evolved to be a pivotal technique in ensuring secure wireless communication. This paper presents a comprehensive analysis of the recent developments in physical layer secret key generation (PLSKG). The principle, procedure, techniques and performance metricesare investigated for PLSKG between a pair of users (PSKG) and for a group of users (GSKG). In this paper, a detailed comparison of the various parameters and techniques employed in different stages of key generation such as, channel probing, quantisation, encoding, information reconciliation (IR) and privacy amplification (PA) are provided. Apart from this, a comparison of bit disagreement rate, bit generation rate and approximate entropy is also presented. The work identifies PSKG and GSKG schemes which are practically realizable and also provides a discussion on the test bed employed for realising various PLSKG schemes. Moreover, a discussion on the research challenges in the area of PLSKG is also provided for future research.
Lightweight session key agreement schemes are expected to play a central role in building Internet of things (IoT) security in sixth-generation (6G) networks. A well-established approach deriving from the physical layer is a secret key generation (SKG) from shared randomness (in the form of wireless fading coefficients). However, although practical, SKG schemes have been shown to be vulnerable to active attacks over the initial "advantage distillation" phase, throughout which estimates of the fading coefficients are obtained at the legitimate users. In fact, by injecting carefully designed signals during this phase, a man-in-the-middle (MiM) attack could manipulate and control part of the reconciled bits and thus render SKG vulnerable to brute force attacks. Alternatively, a denial of service attack can be mounted by a reactive jammer. In this paper, we investigate the impact of injection and jamming attacks during the advantage distillation in a multiple-input-multiple-output (MIMO) system. First, we show that a MiM attack can be mounted as long as the attacker has one extra antenna with respect to the legitimate users, and we propose a pilot randomization scheme that allows the legitimate users to successfully reduce the injection attack to a less harmful jamming attack. Secondly, by taking a game-theoretic approach we evaluate the optimal strategies available to the legitimate users in the presence of reactive jammers.
This paper presents a novel group secret key generation (GSKG) protocol for multi-user wireless systems with a star topology. In contrast to conventional methods relying on pairwise key derivation followed by reconciliation, the proposed approach enables the central node to directly select a group secret key uniformly at random across the full quantization space. This eliminates the need for intermediate pairwise keys, significantly reducing computational complexity, communication overhead, and latency. To ensure consistent group key reconstruction, we introduce two lightweight, non-coding reconciliation techniques: One-Sided Centering (OSC) and Quantization Pattern Alternation (QPA). Unlike coding-based reconciliation in conventional schemes, OSC and QPA allow the central node to transmit helper data – derived from adjusted measurements or shifted quantization grids – to peripheral nodes. This helper data not only aligns their channel observations with the selected quantization region, but also implicitly distributes the group key. Thus, reconciliation and distribution are seamlessly integrated into a unified protocol. The proposed GSKG framework supports both fully and partially cooperative scenarios and remains robust against unreliable or compromised nodes by selectively omitting or perturbing helper data. Furthermore, a concatenation-based group key construction method exploits existing bidirectional channel measurements to generate multiple key segments, enhancing throughput without additional channel probing. Extensive simulations validate the scheme’s performance in terms of key disagreement rate, key generation rate, computational efficiency, and robustness against eavesdropping. The results confirm that the protocol offers high scalability and security, making it a practical and efficient solution for group key establishment in IoT and other resource-constrained wireless applications.
Physical-layer group secret-key (GSK) generation is an effective way of generating secret keys in wireless networks, wherein the nodes exploit inherent randomness in the wireless channels to generate group keys, which are subsequently applied to secure messages while broadcasting, relaying, and other network-level communications. While existing GSK protocols focus on securing the common source of randomness from external eavesdroppers, they assume that the legitimate nodes of the group are trusted. In this paper, we address insider attacks from the legitimate participants of the wireless network during the key generation process. Instead of addressing conspicuous attacks such as switching-off communication, injecting noise, or denying consensus on group keys, we introduce stealth attacks that can go undetected against state-of- the-art GSK schemes. We propose two forms of attacks, namely: (i) different-key attacks, wherein an insider attempts to generate different keys at different nodes, especially across nodes that are out of range so that they fail to recover group messages despite possessing the group key, and (ii) low-rate key attacks, wherein an insider alters the common source of randomness so as to reduce the key-rate. We also discuss various detection techniques, which are based on detecting anomalies and inconsistencies on the channel measurements at the legitimate nodes. Through simulations we show that GSK generation schemes are vulnerable to insider-threats, especially on topologies that cannot support additional secure links between neighbouring nodes to verify the attacks.