Results 1 - 10
of
18
Secrecy rates in the broadcast channel with confidential messages and external eavesdroppers,” submitted to
- IEEE Trans. Wireless Commun
"... ar ..."
(Show Context)
Physical layer security in downlink multi-antenna cellular networks,” submitted to
- IEEE Trans. Commun
"... All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately. ..."
Abstract
-
Cited by 2 (2 self)
- Add to MetaCart
(Show Context)
All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.
Relay-selection improves the security-reliability trade-off in cognitive radio systems
- IEEE Trans. Commun
, 2015
"... ar ..."
Joint scheduling & jamming for data secrecy in wireless networks
- Proc. IEEE WiOpt 2013
, 2013
"... Abstract—The broadcast nature of the wireless medium jeopar-dizes secure transmissions. Cryptographic measures fail to ensure security when eavesdroppers have superior computational capa-bility; however, it can be assured from information theoretic secu-rity approaches. We use physical layer securit ..."
Abstract
-
Cited by 1 (1 self)
- Add to MetaCart
(Show Context)
Abstract—The broadcast nature of the wireless medium jeopar-dizes secure transmissions. Cryptographic measures fail to ensure security when eavesdroppers have superior computational capa-bility; however, it can be assured from information theoretic secu-rity approaches. We use physical layer security to guarantee non-zero secrecy rate in single source, single destination multi-hop networks with eavesdroppers for two cases: when eavesdropper locations and channel gains are known and when their positions are unknown. We propose a two-phase solution which consists of finding activation sets and then obtaining transmit powers subject to SINR constraints for the case when eavesdropper locations are known. We introduce methods to find activation sets and compare their performance. Necessary but reasonable approximations are made in power minimization formulations for tractability reasons. For scenarios with no eavesdropper location information, we suggest vulnerability region (the area having zero secrecy rate) minimization over the network. Our results show that in the absence of location information average number of eavesdroppers who have access to data is reduced. I.
Enhancing Wireless Communication Privacy with Artificial Fading
"... Abstract—This paper addresses the problem of anti-eavesdropping in wireless network physical layer. The main contribution of this paper is twofold. First, we propose a novel concept of artificial fading that is produced by double-beam switching of smart antenna array to intentionally corrupt unwante ..."
Abstract
-
Cited by 1 (1 self)
- Add to MetaCart
(Show Context)
Abstract—This paper addresses the problem of anti-eavesdropping in wireless network physical layer. The main contribution of this paper is twofold. First, we propose a novel concept of artificial fading that is produced by double-beam switching of smart antenna array to intentionally corrupt unwanted wireless communication links. Second, we develop a physical layer anti-eavesdropping scheme to minimize the unnecessary coverage area, and hence, lower the chance of being eavesdropped. Our anti-eavesdropping scheme employs smart antenna with two synthesized radiation patterns, which are optimized to provide good signal quality to the intended receiver, while their overlap apart from the intended direction is minimized. During the transmission, the transmitter period-ically alternates between the two optimized patterns at a high frequency, which produces severe fading to the received signal in undesired directions. Since such signals are corrupted and cannot be decoded, eavesdropping is prevented. Simulation experiments show that our anti-eavesdropping scheme outperforms single pattern beamforming in reducing the unnecessary coverage area exposed to eavesdroppers. I.
A study on secure pilot signal design for OFDM systems
"... Abstract-In this paper, we investigate a physical layer security technique in an orthogonal frequency-division multiplexing (OFDM) based wireless communications. In an OFDM system, the legitimate transmitter (Alice) can increase secrecy capacity with proper power allocation and/or bit loading metho ..."
Abstract
- Add to MetaCart
(Show Context)
Abstract-In this paper, we investigate a physical layer security technique in an orthogonal frequency-division multiplexing (OFDM) based wireless communications. In an OFDM system, the legitimate transmitter (Alice) can increase secrecy capacity with proper power allocation and/or bit loading methods for example by maximizing mutual information for own communication, i.e. between Alice and the legitimate receiver (Bob). The reason of increasing secrecy capacity is that the power allocation is suitable for the channel state between Alice and Bob but not suitable for the channel state between Alice and the eavesdropper (Eve). In this paper, we investigate a new approach where dummy data is exploited to achieve further improvement of secrecy capacity. Specifically, real data and dummy data are implemented in transmit OFDM symbols and secure pilot signals are employed to inform the receiver about their respective locations. Two secure pilot signal designs are introduced and in both of them it is designed that Bob can easily detect correct real data locations but not for Eve. One of them uses fake pilot signals that cause Eve to mistakenly select dummy data as real data. Numerical results will show that secrecy capacity performance of the first secure pilot signal based secure communication (not using fake signal) is slightly less than the performance of water filling algorithm. One significant advantage of the first secure pilot signal based secure communication is that the computational cost should be significantly less than the water filling algorithm. In addition, we will show that fake pilot signal based secure communication can provide significant gain in secrecy capacity while the computational cost is still small.
Opportunistic Relay and Jammer Cooperation Techniques for Physical-Layer Security in Buffer-aided Relay Networks
"... Abstract-In this paper, we investigate opportunistic relay and jammer cooperation schemes in multiple-input multiple-output (MIMO) buffer-aided relay networks. The network consists of one source, an arbitrary number of relay nodes, legitimate users and eavesdroppers, with the constraints of physica ..."
Abstract
- Add to MetaCart
(Show Context)
Abstract-In this paper, we investigate opportunistic relay and jammer cooperation schemes in multiple-input multiple-output (MIMO) buffer-aided relay networks. The network consists of one source, an arbitrary number of relay nodes, legitimate users and eavesdroppers, with the constraints of physical layer security. We propose an algorithm to select a set of relay nodes to enhance the legitimate users' transmission and another set of relay nodes to perform jamming of the eavesdroppers. With Inter-Relay interference (IRI) taken into account, interference cancellation can be implemented to assist the transmission of the legitimate users. Secondly, IRI can also be used to further increase the level of harm of the jamming signal to the eavesdroppers. By exploiting the fact that the jamming signal can be stored at the relay nodes, we also propose a hybrid algorithm to set a signal-to-interference and noise ratio (SINR) threshold at the node to determine the type of signal stored at the relay node. With this separation, the signals with high SINR are delivered to the users as conventional relay systems and the low SINR performance signals are stored as potential jamming signals. Simulation results show that the proposed techniques obtain a significant improvement in secrecy rate over previously reported algorithms. Index Terms-Physical-layer security techniques, secrecy-rate analysis, relay selection, jamming techniques. I. INTRODUCTION In broadcast channels, secure transmission is difficult to achieve due to the broadcast nature of wireless communication systems. Traditional encryption techniques are implemented in the network layer. With complex algorithms, encryption keys which are nearly unbreakable are generated to ensure security while their costs are extremely high. To reduce the costs of encryption algorithms, researchers are investigating novel security techniques in the physical layer of wireless systems. Physical-layer security has been first illustrated in
Buffer-Aided Relaying for Two-Hop Secure Communication
"... Abstract—We consider using a buffer-aided relay to enhance security for two-hop half-duplex relay networks with an external eavesdropper. We propose a link selection scheme that adapts reception and transmission time slots based on channel quality, while considering both the two-hop transmission eff ..."
Abstract
- Add to MetaCart
(Show Context)
Abstract—We consider using a buffer-aided relay to enhance security for two-hop half-duplex relay networks with an external eavesdropper. We propose a link selection scheme that adapts reception and transmission time slots based on channel quality, while considering both the two-hop transmission efficiency and security. Closed-form expressions for the secrecy throughput and the secrecy outage probability (SOP) are derived, and the selection parameters are optimized to maximize the secrecy throughput or minimize the SOP. We then analyze two sub-optimal link selection schemes that in general only require a line search to solve the optimization problem, and we show that, under certain conditions, these approaches also admit closed-form solutions. All schemes are discussed in the context of two different scenarios where the relay either knows or does not know the channel to the legiti-mate receiver. In the former case, the relay adopts adaptive-rate transmission, whereas for the latter, it uses fixed-rate transmis-sion. Numerical results show that buffer-aided relaying provides a significant improvement in security compared with conventional unbuffered relaying. Furthermore, the performance of the sub-optimal schemes is shown to approach the optimal one for certain ranges of signal-to-noise-ratio (SNR) or SOP constraints. Index Terms—Buffered relay, wiretap channel, physical layer security, outage probability, relay networks. I.
Transactions on Wireless Communications 1 Limited Rate Feedback Scheme for Resource Allocation in Secure Relay-Assisted OFDMA Networks
"... Abstract—In this paper, we consider the problem of resource allocation for secure communications in decode-and-forward (DF) relay-assisted Orthogonal Frequency-Division Multiple Ac-cess (OFDMA) networks. In our setting, users want to securely communicate to the base station (BS) with the help of a s ..."
Abstract
- Add to MetaCart
(Show Context)
Abstract—In this paper, we consider the problem of resource allocation for secure communications in decode-and-forward (DF) relay-assisted Orthogonal Frequency-Division Multiple Ac-cess (OFDMA) networks. In our setting, users want to securely communicate to the base station (BS) with the help of a set of relay stations (RSs) in the presence of multiple eavesdroppers. We assume that all channel state information (CSI) of the legitimate links and only the channel distribution information (CDI) of the eavesdropper links are available. We formulate our problem as an optimization problem whose objective is to maximize the sum secrecy rate of the system subject to individual transmit power constraint for each user and RS. As a first work which considers limited feedback schemes for secure communications in cooperative OFDMA networks, we consider the limited-rate feedback case where in addition to transmit power and subcarrier assignments, channel quantization should be performed and boundary regions of channels should be computed. We further consider the noisy feedback channel. We solve our problem using the dual Lagrange approach and propose an iterative algorithm whose convergence is analyzed. Using simulations, we evaluate the performance of the proposed scheme in numerous situations. Index Terms – Physical (PHY) layer security, limited feedback, eavesdropper, decode-and-forward (DF) relay. I.