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62
The secrecy capacity of the MIMO wiretap channel
, 2008
"... We consider the MIMO wiretap channel, that is a MIMO broadcast channel where the transmitter sends some confidential information to one user which is a legitimate receiver, while the other user is an eavesdropper. Perfect secrecy is achieved when the the transmitter and the legitimate receiver can c ..."
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Cited by 171 (1 self)
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We consider the MIMO wiretap channel, that is a MIMO broadcast channel where the transmitter sends some confidential information to one user which is a legitimate receiver, while the other user is an eavesdropper. Perfect secrecy is achieved when the the transmitter and the legitimate receiver can communicate at some positive rate, while insuring that the eavesdropper gets zero bits of information. In this paper, we compute the perfect secrecy capacity of the multiple antenna MIMO broadcast channel, where the number of antennas is arbitrary for both the transmitter and the two receivers.
Wireless information-theoretic security - part I: Theoretical aspects
- IEEE Trans. on Information Theory
, 2006
"... In this two-part paper, we consider the transmission of confidential data over wireless wiretap channels. The first part presents an information-theoretic problem formulation in which two legitimate partners communicate over a quasi-static fading channel and an eavesdropper observes their transmissi ..."
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Cited by 162 (12 self)
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In this two-part paper, we consider the transmission of confidential data over wireless wiretap channels. The first part presents an information-theoretic problem formulation in which two legitimate partners communicate over a quasi-static fading channel and an eavesdropper observes their transmissions through another independent quasi-static fading channel. We define the secrecy capacity in terms of outage probability and provide a complete characterization of the maximum transmission rate at which the eavesdropper is unable to decode any information. In sharp contrast with known results for Gaussian wiretap channels (without feedback), our contribution shows that in the presence of fading information-theoretic security is achievable even when the eavesdropper has a better average signal-to-noise ratio (SNR) than the legitimate receiver — fading thus turns out to be a friend and not a foe. The issue of imperfect channel state information is also addressed. Practical schemes for wireless information-theoretic security are presented in Part II, which in some cases comes close to the secrecy capacity limits given in this paper.
The relay-eavesdropper channel: Cooperation for secrecy
- IEEE Trans. on Inf. Theory
, 2006
"... This paper establishes the utility of user cooperation in facilitating secure wireless communications. In particular, the four-terminal relay-eavesdropper channel is introduced and an outer-bound on the optimal rate-equivocation region is derived. Several cooperation strategies are then devised and ..."
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Cited by 158 (7 self)
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This paper establishes the utility of user cooperation in facilitating secure wireless communications. In particular, the four-terminal relay-eavesdropper channel is introduced and an outer-bound on the optimal rate-equivocation region is derived. Several cooperation strategies are then devised and the corresponding achievable rate-equivocation region are characterized. Of particular interest is the novel Noise-Forwarding (NF) strategy, where the relay node sends codewords independent of the source message to confuse the eavesdropper. This strategy is used to illustrate the deaf helper phenomenon, where the relay is able to facilitate secure communications while being totally ignorant of the transmitted messages. Furthermore, NF is shown to increase the secrecy capacity in the reversely degraded scenario, where the relay node fails to offer performance gains in the classical setting. The gain offered by the proposed cooperation strategies is then proved theoretically and validated numerically in the additive White Gaussian Noise (AWGN) channel. I.
Secrecy Capacity of Wireless Channels
- in Proc. IEEE Int. Symp. Information Theory (ISIT
, 2006
"... Abstract — We consider the transmission of confidential data over wireless channels with multiple communicating parties. Based on an information-theoretic problem formulation in which two legitimate partners communicate over a quasi-static fading channel and an eavesdropper observes their transmissi ..."
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Cited by 113 (4 self)
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Abstract — We consider the transmission of confidential data over wireless channels with multiple communicating parties. Based on an information-theoretic problem formulation in which two legitimate partners communicate over a quasi-static fading channel and an eavesdropper observes their transmissions through another independent quasi-static fading channel, we define the secrecy capacity in terms of outage probability and provide a complete characterization of the maximum transmission rate at which the eavesdropper is unable to decode any information. In sharp contrast with known results for Gaussian wiretap channels (without feedback), our contribution shows that in the presence of fading information-theoretic security is achievable even when the eavesdropper has a better average signal-to-noise ratio (SNR) than the legitimate receiver — fading thus turns out to be a friend and not a foe. I.
Secret communication using artificial noise
- In IEEE Vehicular Technology Conference
, 2005
"... Abstract — The problem of secret communication between two nodes over a wireless link is considered, where a passive eavesdropper may overhear the communication. It is desired that the eavesdropper be unable to decode the message. We show that secrecy can be achieved by adding artificially generated ..."
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Cited by 87 (1 self)
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Abstract — The problem of secret communication between two nodes over a wireless link is considered, where a passive eavesdropper may overhear the communication. It is desired that the eavesdropper be unable to decode the message. We show that secrecy can be achieved by adding artificially generated noise to the information bearing signal such that it does not degrade the intended receiver’s channel. We consider two different scenarios; one in which the transmitter has multiple transmit antennas and the other in which the transmitter has a single antenna but ‘helper ’ nodes are available. In the multiple antenna scenario, the degrees of freedom provided by the multiple antennas is used to generate noise intelligently so that it degrades only the eavesdropper’s channel. In the multiple helper scenario, even though the transmitter does not have multiple antennas, the helper nodes simulate the effect of multiple antennas and allow the transmitter to generate artificial noise as in the previous case.
Securing wireless systems via lower layer enforcements
- in Proceedings of the 5th ACM workshop on Wireless security, 2006
"... Although conventional cryptographic security mechanisms are essential to the overall problem of securing wireless networks, these techniques do not directly leverage the unique properties of the wireless domain to address security threats. The properties of the wireless medium are a powerful source ..."
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Cited by 62 (2 self)
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Although conventional cryptographic security mechanisms are essential to the overall problem of securing wireless networks, these techniques do not directly leverage the unique properties of the wireless domain to address security threats. The properties of the wireless medium are a powerful source of domain-specific information that can complement and enhance traditional security mechanisms. In this paper, we propose to utilize the fact that the radio channel decorrelates rapidly in space, time and frequency in order to to establish new forms of authentication and confidentiality that operate at the physical layer and can be used to facilitate cross-layer security paradigms. Specifically, for authentication services, we illustrate two channel probing techniques that can be used to verify the authenticity of a transmitter. Similarly, for confidentiality, we examine several strategies for establishing shared secrets/keys between two communicators using the wireless medium. These strategies range from extracting keys from channel state information, to utilizing the channel variability to secretly disseminate keys. We then validate the feasibility of using physical layer techniques for securing wireless systems by presenting results from experiments involving the USRP/GNURadio software defined radio platform.
Secure wireless communications via cooperation
- in Proc. Allerton Conf. Commun., Control, Comput
, 2008
"... Abstract — The feasibility of physical-layer-based security approaches for wireless communications in the presence of one or more eavesdroppers is hampered by channel conditions. In this paper, cooperation is investigated as an approach to overcome this problem and improve the performance of secure ..."
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Cited by 40 (10 self)
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Abstract — The feasibility of physical-layer-based security approaches for wireless communications in the presence of one or more eavesdroppers is hampered by channel conditions. In this paper, cooperation is investigated as an approach to overcome this problem and improve the performance of secure communications. In particular, a decode-and-forward (DF) based cooperative protocol is considered, and the objective is to design the system for secrecy capacity maximization or transmit power minimization. System design for the DF-based cooperative protocol is first studied by assuming the availability of global channel state information (CSI). For the case of one eavesdropper, an iterative scheme is proposed to obtain the optimal solution for the problem of transmit power minimization. For the case of multiple eavesdroppers, the problem of secrecy capacity maximization or transmit power minimization is in general intractable. Suboptimal system design is proposed by adding an additional constraint, i.e., the complete nulling of signals at all eavesdroppers, which yields simple closed-form solutions for the aforementioned two problems. Then, the impact of imperfect CSI of eavesdroppers on system design is studied, in which the ergodic secrecy capacity is of interest. I.
Robust beamforming for security in MIMO wiretap channels with imperfect CSI
- IEEE Trans. Signal Process
, 2011
"... Abstract—In this paper, we investigate methods for reducing the likelihood that a message transmitted between two multi-antenna nodes is intercepted by an undetected eavesdropper. In particular, we focus on the judicious transmission of artificial interference to mask the desired signal at the time ..."
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Cited by 30 (4 self)
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Abstract—In this paper, we investigate methods for reducing the likelihood that a message transmitted between two multi-antenna nodes is intercepted by an undetected eavesdropper. In particular, we focus on the judicious transmission of artificial interference to mask the desired signal at the time it is broadcast. Unlike previous work that assumes some prior knowledge of the eavesdropper’s channel and focuses on maximizing secrecy capacity, we consider the case where no information regarding the eavesdropper is available, and we use signal-to-interference-plus-noise-ratio (SINR) as our performance metric. Specifically, we focus on the problem of maximizing the amount of power available to broadcast a jamming signal intended to hide the desired signal from a potential eavesdropper, while maintaining a prespecified SINR at the desired receiver. The jamming signal is designed to be orthogonal to the information signal when it reaches the desired receiver, assuming both the receiver and the eavesdropper employ optimal beamformers and possess exact channel state information (CSI). In practice, the assumption of perfect CSI at the transmitter is often difficult to justify. Therefore, we also study the resulting performance degradation due to the presence of imperfect CSI, and we present robust beamforming schemes that recover a large fraction of the performance in the perfect CSI case. Numerical simulations verify our analytical performance predictions, and illustrate the benefit of the robust beamforming schemes. I.
Using the Physical Layer for Wireless Authentication in Time-Variant Channels
, 2008
"... The wireless medium contains domain-specific information that can be used to complement and enhance traditional security mechanisms. In this paper we propose ways to exploit the spatial variability of the radio channel response in a rich scattering environment, as is typical of indoor environments. ..."
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Cited by 30 (4 self)
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The wireless medium contains domain-specific information that can be used to complement and enhance traditional security mechanisms. In this paper we propose ways to exploit the spatial variability of the radio channel response in a rich scattering environment, as is typical of indoor environments. Specifically, we describe a physical-layer authentication algorithm that utilizes channel probing and hypothesis testing to determine whether current and prior communication attempts are made by the same transmit terminal. In this way, legitimate users can be reliably authenticated and false users can be reliably detected. We analyze the ability of a receiver to discriminate between transmitters (users) according to their channel frequency responses. This work is based on a generalized channel response with both spatial and temporal variability, and considers correlations among the time, frequency and spatial domains. Simulation results, using the ray-tracing tool WiSE to generate the time-averaged response, verify the efficacy of the approach under realistic channel conditions, as well as its capability to work under unknown channel variations.
Robust Secure Transmission in MISO Channels Based on Worst-Case Optimization
- IEEE Trans. Signal Process
, 2012
"... Abstract—This paper studies robust transmission schemes for MISO wiretap channels with imperfect channel state information (CSI) for the eavesdropper link. Both the cases of direct transmis-sion and cooperative jamming with a helper are investigated. The error in the eavesdropper’s CSI is assumed to ..."
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Cited by 27 (5 self)
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Abstract—This paper studies robust transmission schemes for MISO wiretap channels with imperfect channel state information (CSI) for the eavesdropper link. Both the cases of direct transmis-sion and cooperative jamming with a helper are investigated. The error in the eavesdropper’s CSI is assumed to be norm-bounded, and robust transmit covariance matrices are obtained based on worst-case secrecy rate maximization, under both individual and global power constraints. Numerical results show the advantage of the proposed robust design. In particular, under a global power constraint, although cooperative jamming is not necessary for optimal transmission with perfect eavesdropper’s CSI, we show that robust jamming support can increase the secrecy rate in the presence of channel mismatch. I.
