Most of the existing works on group secret key (GSK) generation are based on pairwise key which wasting the total time and power of the group users. We present a cooperative GSK generation algorithm via star topology with one central node and one reference node. After channel estimation, secure network coding technique is employed by the central node to help all the group users exploit the randomness of reference channel with nothing about that leaking to the eavesdropper. Then all the group users agree on a secret key from the correlative observations of the reference channel in one information reconciliation phase. In addition, the expression of achievable secret key rate is derived. Theoretical and Monte Carlo simulation results validate the performance of our proposed algorithm.
Most of the existing works on group secret key (GSK) generation are based on pairwise key which wasting the total time and power of the group users. We present a cooperative GSK generation algorithm via star topology with one central node and one reference node. After channel estimation, secure network coding technique is employed by the central node to help all the group users exploit the randomness of reference channel with nothing about that leaking to the eavesdropper. Then all the group users agree on a secret key from the correlative observations of the reference channel in one information reconciliation phase. In addition, the expression of achievable secret key rate is derived. Theoretical and Monte Carlo simulation results validate the performance of our proposed algorithm.
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.
This paper explores physical layer group key generation in wireless relay networks with a star topology. In this setup, the relay node plays the role of either a trusted or untrusted central node, while one legitimate node (Alice) acts as the reference node. The channel between the relay and Alice serves as the reference channel. To enhance security during the channel measurement stage, a cooperative jamming-based scheme is proposed in this paper. This scheme allows the relay to obtain superimposed channel observations from both the reference channel and other relay channels. Then, a public discussion is utilized to enable all nodes to obtain estimates of the reference channel. Subsequently, the legitimate nodes can agree on a secret key (SK) that remains secret from the eavesdropper (Eve), or a private key (PK) that needs to be secret from both the relay and Eve. This paper also derives the lower and upper bounds of the SK/PK capacity. Notably, it demonstrates that there exists only a small constant difference between the SK/PK upper and lower bounds in the high signal-to-noise ratio (SNR) regime. Simulation results confirm the effectiveness of the proposed scheme for ensuring security and efficiency of group key generation.
The Internet of Things technology is one of the important directions of Smart Grid research, involving many wireless sensors and communication facilities, and has high requirements for security. The physical layer security technology can effectively solve the security problems under wireless communication. As the most common application scenario of wireless communication is multi-node wireless network communication, group secret key (GSK) based on physical layer security and information theory security is gradually attracting investigator’s interest. In this paper, a novel physical layer GSK generation scheme based on code-domain exchange of channel information in mesh network is proposed. Instead of traditional side-information exchange in symbol-domain, error-correcting code is applied to finish information exchange and reconciliation simultaneously in code-domain. Each node processes the known channel bit sequence and then encodes it to generate a check sequence. After broadcasting the check bit sequence to other nodes, each node decodes the received check bit sequences to obtained the unknown channel information. The simulation results show that the scheme can effectively reduce the times of information exchanges while keeping a good performance including low bit error rate and low block error rate.
In unmanned aerial vehicle (UAV) swarm networks, a group secret key (GSK) is required to enable secured UAV-UAV communications, multicast, and broadcast transmission. Moreover, it can be used for device authentication. Therefore, this paper proposes an efficient GSK protocol denoted as the sequential secret group key (SSGK) algorithm for distributed UAV swarmsecured communications. The proposed protocol utilizes network coding to generate cooperation information that is transmitted on the channel and is uncorrelated with the generated secret key. The proposed protocol depends on the pairwise key generation (PKG) process between pairs of UAVs. However, not all possible pairwise agreements are performed to minimize the time and signaling overhead, i.e., the pairwise key agreement is performed only between selected UAVs as a compromise between the required overhead transmission resources and the achieved redundancy level. The obtained results show that a redundancy level of 4 is sufficient to provide a reliable GSK generation process. The results also show that the performance of the key generation process highly depends on the channelbit error rate (BER), the number of UAVs, and the key length.
The secret group key generation based on physical layer security and information theory security has attracted increasing research interest. In this paper, we propose a scheme to establish the secret group key with the cooperation of all the nodes. To ensure the security of the group communication, a protocol is proposed to implement the collaborative secret group key via circle network topology. We subsequently analyze the achievable theoretical upper bound of the secret group key rate for circle topology in the presence of an eavesdropper. The simulation result shows that the protocol doesn't only assign the computation and broadcast to each node, but also obviously increase the group key generation rate than a benchmark scheme. We further analyze the impact of node number and SNR on the achievable secrecy rate.
In this paper, we propose a novel non-orthogonal multiple access (NOMA)-based physical-layer group secret key distribution (GSKD) from a base station (BS) to multiple legitimate users for a star network in the presence of an eavesdropper. In the proposed scheme, a random group secret key generated at the BS is distributed to legitimate users in an information-theoretically secure manner. More specifically, the BS and each user share a secret key from the associated channel state information (CSI), which is then used to encrypt the group secret key with a one-time pad. Then, each of the encrypted group secret keys is superimposed and efficiently broadcast to the users in the NOMA downlink. Each user extracts the group secret key with the aid of successive interference cancellation of the superimposed signal and decryption based on the user-specific secret key generated from CSI. Moreover, we derive the theoretical group key rate bound of the proposed scheme. Our performance results demonstrate that the proposed NOMA-based GSKD scheme outperforms the conventional benchmark schemes while investigating the effects of information reconciliation based on Bose-Chaudhuri-Hocquenghem (BCH) codes, as well as channel coding based on polar codes.