This paper presents an investigation of the secrecy capacity in device-to-device (D2D) enabled cellular network under the collusion of eavesdroppers. We provide the closed-form expressions for the probability of achieving non-zero secrecy capacity of the downlink channel between cellular base-station (BS) and user in the presence of D2D nodes and eavesdroppers. Furthermore, two techniques are used for the simple yet exact evaluation of the average secrecy rate using moment generating functions with and without interference. The impact of transmission factors, path loss exponents, and node density is analysed in numerical results. In contrast to the general notion of interference-aided secure communication, it has been shown that the interference does not impact the secrecy rate under the collusion of eavesdroppers.
This paper presents an investigation of the secrecy capacity in device-to-device (D2D) enabled cellular network under the collusion of eavesdroppers. We provide the closed-form expressions for the probability of achieving non-zero secrecy capacity of the downlink channel between cellular base-station (BS) and user in the presence of D2D nodes and eavesdroppers. Furthermore, two techniques are used for the simple yet exact evaluation of the average secrecy rate using moment generating functions with and without interference. The impact of transmission factors, path loss exponents, and node density is analysed in numerical results. In contrast to the general notion of interference-aided secure communication, it has been shown that the interference does not impact the secrecy rate under the collusion of eavesdroppers.
In this paper, we investigate secure D2D communications underlay cellular network using artificial noise. In wireless communications where a single eavesdropper is present, artificial noise can effectively degrade the eavesdropper performance and increase the secrecy rate. Since the user and the device share radio resources in an underlay network, it causes interference with each other. Thus, the sum secrecy rate of the user and the device are considered to enhance the entire network. In order to maximize the sum secrecy rate, we designed a precoding signal vector and an artificial precoding matrix and found the optimal power allocation for the signal and the artificial noise. Moreover, given the base station power, we obtained the upper limit of device power for achieving the corresponding secrecy rate.
We perform an analysis of the secrecy outage and transmission capacity of random networks under Nakagami-m fading with colluding eavesdroppers, in the asymptotic case of large reference signal-to-noise ratios. In literature, secrecy analysis from the perspective of collusion pool has still not been well characterized. Considering a network model that accounts for uncertainties both in node locations and channel coefficients, we approximate the distribution of the aggregate path gain received by a collusion of eavesdroppers. Using this result, the asymptotic secrecy rate distribution, the secrecy outage probability, and the secrecy transmission capacity of random networks with colluding eavesdroppers are obtained, with basic factors such as density of nodes, the guarding distance, and the fading figure all accounted for by explicit parameters. Since secrecy in low-outage random networks are found to be most significant when the density of active nodes is small, the expressions derived can be seen as upper-bounds on the three aforementioned secrecy performance metrics in random networks, offering particular insight on the impact of fading, density, and guarding distances, while taking into account cooperation among eavesdroppers. Furthermore, we give a bound on colluding pool size, which is pragmatic in creating a nonprotected communication zone for the typical destination.
In a powerful secrecy attack, eavesdroppers can collude, i.e., they can share their observations. Securing information in such a scenario will be an even more challenging task compared to non-colluding case. We here analyze the effect of eavesdropper collusion on the achievable performance in both the path loss and ergodic multi-path fading models. We provide two results: 1) For the Poisson point process model in a random extended network, if the legitimate nodes have unit intensity (λ = 1) and the colluding eavesdroppers have an intensity of λe= O((log n)-(2+p)) for any p > 0, almost all of the nodes can achieve a secure rate of Ω(1/(√n)); I and 2) In the K-user Gaussian interference channel with E external colluding eavesdroppers, a secure degrees of freedom of η =[1/2-E/K]+per frequency-time slot is achievable for each user in the ergodic setting (in the absence of the eavesdropper channel state information).
This letter examines the physical layer security of a cellular network with inband underlay relay-aided Device-to-Device (D2D) communication, considering the scenario where the channel state information is outdated. The relay node, which operates in a full-duplex mode, can concurrently serve as a friendly jammer to enhance the cellular network secrecy performance while increasing the D2D communication data transmission. A passive eavesdropper utilizes combining approaches to combine the eavesdropping signals. Closed-form expressions for the D2D outage probability and the secrecy outage probability are derived. Furthermore, the asymptotic results are also provided.
This paper analyzes the secrecy outage probability of a cellular downlink system which consists of multiple users, one base station (BS), and one eavesdropper in the presence of co-channel interferers, where the BS transmits its signals to users which are distributed according to a Poisson point process with a fixed density, while the eavesdropper attempts to tap the transmission from the BS to the users. To enhance the transmission security against eavesdropping, we propose two multiuser scheduling schemes, namely, the partial channel state information (CSI) aided user scheduling (PCSI-US) scheme where only the CSIs of users are available without knowing the co-channel interferers' CSIs and the full CSI aided user scheduling (FCSI-US) scheme which requires the CSIs of both users and interferers. For comparison purposes, the conventional round-robin scheduling scheme is also considered as a baseline. We derive closed-form expressions of the secrecy outage probability for the proposed PCSI-US and FCSI-US as well as conventional round-robin scheduling schemes in co-channel interference (CCI) environments. Numerical results show that the proposed FCSI-US and PCSI-US schemes outperform the conventional round-robin scheduling in terms of their secrecy outage probabilities, where FCSI-US achieves the best secrecy outage performance in CCI environments. It is also demonstrated that increasing the mean number of users has a marginal effect on the secrecy performance of conventional round-robin scheduling, which can significantly decrease the secrecy outage probabilities of PCSI-US and FCSI-US schemes. This further validates the secrecy effectiveness of the proposed user scheduling methods in terms of combating the CCI.
In this paper, we study secrecy performance of downlink transmission in large-scale cellular networks where randomly distributed Base Stations (BSs) communicate to an intended mobile user under the scenario of cooperative eavesdropping. Based on the stochastic geometry theory, we first derive the closed-form expressions of the secrecy outage probability and the average secrecy rate in the simple scenario of non-cooperative eavesdropping, where each eavesdropper decodes the messages independently. Then, the secrecy performance analysis is extended to more hazardous cooperative scenario in which all eavesdroppers freely share their observations to decode the confidential messages. Finally, our results show that the small-scale fading has a greater effect on secrecy performance in small density of eavesdroppers. Moreover, the performance difference between the scenario of non-cooperative eavesdropping and cooperative eavesdropping is more obvious, when the path loss exponent or the density of eavesdroppers is small.