We investigate group secret key generation in 5G mmWave Massive MIMO networks and intend to improve the efficiency of channel probing for group key generation. In this paper, a new channel probing strategy for star-topology networks is proposed, which relies on the multiplexing of downlink probing signals, enabled by the hybrid precoding. To improve the group key rates per channel probing, a genetic algorithm (GA) based power allocation algorithm is also proposed. What’s more, to estimate the group key rates based on the probing samples, we propose a scheme for the estimation of group key rates based on the maximum likelihood estimator (MLE). The performance of the proposed scheme on group key rates and bits disagreement ratio (BDR) are provided. The numerical results show that the GA-based downlink channel probing scheme can increase the efficiency of channel probing and have higher group key rates compared with the existing channel probing schemes. When the SNR is 25dB, the key rates of GA-based power allocation scheme are 20% higher than the scheme with the conventional channel probing strategy.
We investigate group secret key generation in 5G mmWave Massive MIMO networks and intend to improve the efficiency of channel probing for group key generation. In this paper, a new channel probing strategy for star-topology networks is proposed, which relies on the multiplexing of downlink probing signals, enabled by the hybrid precoding. To improve the group key rates per channel probing, a genetic algorithm (GA) based power allocation algorithm is also proposed. What’s more, to estimate the group key rates based on the probing samples, we propose a scheme for the estimation of group key rates based on the maximum likelihood estimator (MLE). The performance of the proposed scheme on group key rates and bits disagreement ratio (BDR) are provided. The numerical results show that the GA-based downlink channel probing scheme can increase the efficiency of channel probing and have higher group key rates compared with the existing channel probing schemes. When the SNR is 25dB, the key rates of GA-based power allocation scheme are 20% higher than the scheme with the conventional channel probing strategy.
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.
Shared secret key generation from wireless channel characteristics has attracted a lot of research attention in recent years due to its low computational overhead and potentials to achieve information-theoretic security. In this paper, for millimeter wave (mmWave) Massive MIMO channel, we propose to use new channel characteristics - virtual AoA (Angle of Arrival) and AoD (Angle of Departure), to generate a shared secret key between two devices. Other than reciprocity, AoA and AoD of the virtual channel present sparsity and their estimation is efficient and robust against noise. Through theoretical analysis and extensive simulations, we show that the proposed key generation using virtual AoA and AoD achieves much higher bit agreement ratio than existing mechanisms directly using channel state information. Our method can achieve above 99% bit agreement ratio even under very low SNR (e.g., -10dB), which is not achievable by the existing mechanisms. Besides, in our proposed mechanism, the bit agreement ratio becomes higher when number of antennas increases, along with higher key generate rates achieved per channel sounding.
This paper investigates group secret key generation problems for different types of wireless networks, by exploiting physical layer characteristics of wireless channels. A new group key generation strategy with low complexity is proposed, which combines the well-established point-to-point pairwise key generation technique, the multisegment scheme, and the one-time pad. In particular, this group key generation process is studied for three types of communication networks: 1) the three-node network; 2) the multinode ring network; and 3) the multinode mesh network. Three group key generation algorithms are developed for these communication networks, respectively. The analysis shows that the first two algorithms yield optimal group key rates, whereas the third algorithm achieves the optimal multiplexing gain. Next, for the first two types of networks, we address the time allocation problem in the channel estimation step to maximize the group key rates. This non-convex max-min time allocation problem is first reformulated into a series of geometric programming, and then, a single-condensation-method-based iterative algorithm is proposed. Numerical results are also provided to validate the performance of the proposed key generation algorithms and the time allocation algorithm.
In this work, we present a scheme of physical layer secret key generation for Millimeter wave (mmWave) Massive MIMO system. Our scheme is compatible with current hardware structure and protocols including Analog Beamforming, Massive MIMO, and Beam Sweep. We add a small perturbation angle into the Angle of Arrival (AoA) of the transmitter as the common randomness, which significantly improved the secret key rate without being constrained by the complexity of link initialization protocols and low dynamic of the channel. Therefore, the secret key rate can be enhanced by increasing the number of perturbations. In addition, our scheme can combat co-located eavesdropper (Eve) by utilizing the high directionality of Massive MIMO antenna. Numerical results show that our scheme has a high bit agreement ratio (BAR) between legitimate users while the co-located Eve only gets the BAR around 50%, which indicates that the secrecy of the generated key is well achieved.
This paper by exploiting physical layer characteristics of wireless channel investigates group secret key generation problem for different types of wireless network.A new group key generation strategy with low complexity is proposed, which combines point to point pair-wise key generation technique, the multi-segment scheme and the onetime pad.This group key generation technique works for three types of communication networks: the three node network, the multi node ring and multi node mesh network.For these communication networks three group key generation algorithms are developed, the first two algorithms yield optimal group key rates while the third algorithm gives the optimal multiplexing gain.We address the time allocation problem in the channel estimation step to maximize the group key rate.A series of geometric programming, and a single condensation method based iterative algorithm is proposed in order to solve the non-convex max min problem.To validate the performance of the proposed key generation algorithm and the time allocation problem the numerical results are also been provided.
The bloom of 5G communication and beyond serves as a catalyst for physical layer key generation techniques. In 5G communications systems, many challenges in traditional physical layer key generation schemes, such as co-located eavesdroppers, the high bit disagreement ratio, and high temporal correlation, could be overcome. This article lists the key enabling techniques in 5G wireless networks, which offer opportunities to address existing issues in physical layer key generation. We survey the existing key generation methods and introduce possible solutions for the existing issues. The new solutions include applying the high signal directionality in beamforming to resist co-located eavesdroppers, utilizing the sparsity of millimeter-wave channel to achieve a low bit disagreement ratio under low signal-to-noise ratio, and exploiting hybrid precoding to reduce the temporal correlation among measured samples. Finally, the future trends of physical layer key generation in 5G and beyond communications are discussed.