Physical-layer secret key generation (PSKG) provides a lightweight way for group key (GK) sharing between wireless users in large-scale wireless networks. However, most of the existing works in this field consider only group communication. For a commonly dual-task scenario, where both GK and pairwise key (PK) are required, traditional methods are less suitable for direct extension. For the first time, we discover a security issue with traditional methods in dual-task scenarios, which has not previously been recognized. We propose an innovative segment-based key generation method to solve this security issue. We do not directly use PK exclusively to negotiate the GK as traditional methods. Instead, we generate GK and PK separately through segmentation which is the first solution to meet dual-task. We also perform security and rate analysis. It is demonstrated that our method is effective in solving this security issue from an information-theoretic perspective. The rate results of simulation are also consistent with the our rate derivation.
Physical-layer secret key generation (PSKG) provides a lightweight way for group key (GK) sharing between wireless users in large-scale wireless networks. However, most of the existing works in this field consider only group communication. For a commonly dual-task scenario, where both GK and pairwise key (PK) are required, traditional methods are less suitable for direct extension. For the first time, we discover a security issue with traditional methods in dual-task scenarios, which has not previously been recognized. We propose an innovative segment-based key generation method to solve this security issue. We do not directly use PK exclusively to negotiate the GK as traditional methods. Instead, we generate GK and PK separately through segmentation which is the first solution to meet dual-task. We also perform security and rate analysis. It is demonstrated that our method is effective in solving this security issue from an information-theoretic perspective. The rate results of simulation are also consistent with the our rate derivation.
Physical-layer secret key generation (PSKG) leveraging reciprocal wireless channel has been widely studied in pairwise communication scenarios as it addresses the key distribution problem in traditional security mechanisms. However, PSKG encounters the challenges of low key agreement, information leakage and high system cost when it is extended to produce a secret key for a group of users. In this paper, we propose a lightweight Group secret key generation approach leveraging Non-reconciled received Signal Strength (GNSS). Specifically, pairwise bit sequences with high similarity are firstly extracted and then a group key is securely shared with the protection of these pairwise bit sequences, which prevents the information leakage and sophisticated information reconciliation. Detailed algorithms of GNSS for star and chain networks are presented. Numerical and experimental results demonstrate that GNSS can provide high key agreement, thus enabling key generation technology to be used in a group communication scenario.
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.
In this paper, we consider the problem of secret key generation for multiple parties. Multi-user networks usually require a trusted party to efficiently distribute keys to the legitimate users and this process is a weakness against eavesdroppers. With the help of the physical layer security techniques, users can securely decide on a secret key without a trusted party by exploiting the unique properties of the channel. In this context, we develop a physical layer group key generation scheme that is also based on the ideas of the analog function computation studies. We firstly consider the key generation as a function to be computed over the wireless channel and propose two novel methods depending on the users transmission capability (i.e. half-duplex and full-duplex transmissions). Secondly, we exploit the uniqueness of the prime integers in order to enable the simultaneous transmission of the users for key generation. As a result, our approach contributes to the scalability of the existing physical layer key generation algorithms since all users transmit simultaneously rather than using pairwise communications. We prove that our half-duplex network model reduces the required number of communications for group key generation down to a linear scale. Furthermore, the full-duplex network model reduces to a constant scale.
Physical layer secret key generation (PHYSKG) is a promising technology to provide lightweight and information-theoretically secure key sharing. It has been widely studied in wireless communications and the Internet of Things (IoT). Yet, this technology is nontrivial for large scale wireless networks due to high overhead, insufficient security, and poor adaptability. Recently, artificial intelligence (AI)-based PHYSKG has shown greater performance and higher security with lower overhead than traditional schemes. Although many existing works have been devoted to exploiting AI-based PHYSKG, a scientific review is still missing, but highly anticipated in the literature. In this article, we perform a serious review on AI-based PHYSKG in wireless communications. After a comprehensive introduction to the processing procedure of AI-based PHYSKG, we propose a set of criteria for justifying its performance with regard to key generation efficiency, reliability, security, and generality. Based on these criteria, we review and analyze the state-of-art, focusing on randomness extraction and quantification. On the basis of the review, we further indicate open issues, current challenges, and future research direction in this field.
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.
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.