The Experts below are selected from a list of 43320 Experts worldwide ranked by ideXlab platform
Prakash Narayan  One of the best experts on this subject based on the ideXlab platform.

Secret Key generation for correlated gaussian sources
IEEE Transactions on Information Theory, 2012CoAuthors: Sirin Nitinawarat, Prakash NarayanAbstract:Secret Key generation by multiple terminals is considered based on their observations of jointly distributed Gaussian signals, followed by public communication among themselves. Exploiting an inherent connection between secrecy generation and lossy data compression, two main contributions are made. The first is a characterization of strong Secret Key capacity, and entails a converse proof technique that is valid for realvalued (and not necessarily Gaussian) as well as finitevalued signals. The capacity formula acquires a simple form when the terminals observe “symmetrically correlated” jointly Gaussian signals. For the latter setup with two terminals, considering schemes that involve quantization at one terminal, the best rate of an achievable Secret Key is characterized as a function of quantization rate; Secret Key capacity is attained as the quantization rate tends to infinity. Structured codes are shown to attain the optimum tradeoff between Secret Key rate and quantization rate, constituting our second main contribution.

Secret Key Generation for a Pairwise Independent Network Model
arXiv: Information Theory, 2010CoAuthors: Sirin Nitinawarat, Prakash Narayan, Ye Chunxuan, Alexander Barg, Alexander ReznikAbstract:We consider Secret Key generation for a "pairwise independent network" model in which every pair of terminals observes correlated sources that are independent of sources observed by all other pairs of terminals. The terminals are then allowed to communicate publicly with all such communication being observed by all the terminals. The objective is to generate a Secret Key shared by a given subset of terminals at the largest rate possible, with the cooperation of any remaining terminals. Secrecy is required from an eavesdropper that has access to the public interterminal communication. A (singleletter) formula for Secret Key capacity brings out a natural connection between the problem of Secret Key generation and a combinatorial problem of maximal packing of Steiner trees in an associated multigraph. An explicit algorithm is proposed for Secret Key generation based on a maximal packing of Steiner trees in a multigraph; the corresponding maximum rate of Steiner tree packing is thus a lower bound for the Secret Key capacity. When only two of the terminals or when all the terminals seek to share a Secret Key, the mentioned algorithm achieves Secret Key capacity in which case the bound is tight.

capacity of a shared Secret Key
International Symposium on Information Theory, 2010CoAuthors: Imre Csiszar, Prakash NarayanAbstract:Shannon theoretic shared Secret Key generation by multiple terminals is considered for a source model in which the components of a discrete memoryless multiple source and a noiseless public channel of unlimited capacity are available for accomplishing this goal. A shared Secret Key is generated for distinct coalitions of terminals, with all the terminals cooperating in this task through their public communication. A communication from a terminal can be a function of its observed source component and of all previous communication. Member terminals of a coalition unite in recovering the Key. Secrecy is required from an eavesdropper that observes the public interterminal communication. A singleletter characterization of the shared Secret Key capacity is obtained. When the Key must be concealed additionally from subsets of coalition members, we provide an upper bound for the strict shared Secret Key capacity.

Secret Key generation for a pairwise independent network model
International Symposium on Information Theory, 2008CoAuthors: Sirin Nitinawarat, Prakash Narayan, Alexander Barg, Alexander ReznikAbstract:We investigate Secret Key generation for a ldquopairwise independent networkrdquo model in which every pair of terminals observes correlated sources which are independent of sources observed by all other pairs of terminals. The terminals are then allowed to communicate interactively in multiple rounds over a public noiseless channel of unlimited capacity, with all such communication being observed by all the terminals. The objective is to generate a Secret Key shared by a given subset of terminals at the largest rate possible. All the terminals cooperate in generating the Secret Key, with secrecy being required from an eavesdropper which has access to the public interterminal communication. We provide a (singleletter) formula for the secrecy capacity for this model, and show a natural connection between the problem of Secret Key generation and the combinatorial problem of maximal packing of Steiner trees in an associated multigraph. In particular, we show that the maximum number of Steiner tree packings in the multigraph is always a lower bound for the secrecy capacity. The bound is tight for the case when all the terminals seek to share a Secret Key; the mentioned connection yields an explicit capacityachieving algorithm. This algorithm, which can be executed in polynomial time, extracts a groupwide Secret Key of the optimum rate from the collection of optimum and mutually independent Secret Keys for pairs of terminals.

the Secret Key private Key capacity region for three terminals
International Symposium on Information Theory, 2005CoAuthors: Prakash NarayanAbstract:We consider a model for secrecy generation, with three terminals, by means of public interterminal communication, and examine the problem of characterizing all the rates at which all three terminals can generate a "Secret Key," and  simultaneously  two designated terminals can generate a "private Key" which is effectively concealed from the remaining terminal; both Keys are also concealed from an eavesdropper that observes the public communication. Inner and outer bounds for the "Secret Keyprivate Key capacity region" are derived. Under a certain special condition, these bounds coincide to yield the (exact) Secret Keyprivate Key capacity region
Hao Yin  One of the best experts on this subject based on the ideXlab platform.

Secret Key generation for intelligent reflecting surface assisted wireless communication networks
IEEE Transactions on Vehicular Technology, 2021CoAuthors: Phee Lep Yeoh, Deyou Zhang, Gaojie Chen, Yan Zhang, Hao YinAbstract:We propose and analyze Secret Key generation using intelligent reflecting surface (IRS) assisted wireless communication networks. To this end, we first formulate the minimum achievable Secret Key capacity for an IRS acting as a passive beamformer in the presence of multiple eavesdroppers. Next, we develop an optimization framework for the IRS reflecting coefficients based on the Secret Key capacity lower bound. To derive a tractable and efficient solution, we design and analyze a semidefinite relaxation (SDR) and successive convex approximation (SCA) based algorithm for the proposed optimization. Simulation results show that employing our IRSbased algorithm can significantly improve the Secret Key generation capacity for a widerange of wireless channel parameters.
Phee Lep Yeoh  One of the best experts on this subject based on the ideXlab platform.

Secret Key generation for intelligent reflecting surface assisted wireless communication networks
IEEE Transactions on Vehicular Technology, 2021CoAuthors: Phee Lep Yeoh, Deyou Zhang, Gaojie Chen, Yan Zhang, Hao YinAbstract:We propose and analyze Secret Key generation using intelligent reflecting surface (IRS) assisted wireless communication networks. To this end, we first formulate the minimum achievable Secret Key capacity for an IRS acting as a passive beamformer in the presence of multiple eavesdroppers. Next, we develop an optimization framework for the IRS reflecting coefficients based on the Secret Key capacity lower bound. To derive a tractable and efficient solution, we design and analyze a semidefinite relaxation (SDR) and successive convex approximation (SCA) based algorithm for the proposed optimization. Simulation results show that employing our IRSbased algorithm can significantly improve the Secret Key generation capacity for a widerange of wireless channel parameters.
Alexander Reznik  One of the best experts on this subject based on the ideXlab platform.

Secret Key Generation for a Pairwise Independent Network Model
arXiv: Information Theory, 2010CoAuthors: Sirin Nitinawarat, Prakash Narayan, Ye Chunxuan, Alexander Barg, Alexander ReznikAbstract:We consider Secret Key generation for a "pairwise independent network" model in which every pair of terminals observes correlated sources that are independent of sources observed by all other pairs of terminals. The terminals are then allowed to communicate publicly with all such communication being observed by all the terminals. The objective is to generate a Secret Key shared by a given subset of terminals at the largest rate possible, with the cooperation of any remaining terminals. Secrecy is required from an eavesdropper that has access to the public interterminal communication. A (singleletter) formula for Secret Key capacity brings out a natural connection between the problem of Secret Key generation and a combinatorial problem of maximal packing of Steiner trees in an associated multigraph. An explicit algorithm is proposed for Secret Key generation based on a maximal packing of Steiner trees in a multigraph; the corresponding maximum rate of Steiner tree packing is thus a lower bound for the Secret Key capacity. When only two of the terminals or when all the terminals seek to share a Secret Key, the mentioned algorithm achieves Secret Key capacity in which case the bound is tight.

information theoretically Secret Key generation for fading wireless channels
IEEE Transactions on Information Forensics and Security, 2010CoAuthors: Suhas Mathur, Alexander Reznik, Yogendra C Shah, Wade Trappe, Narayan B MandayamAbstract:The multipathrich wireless environment associated with typical wireless usage scenarios is characterized by a fading channel response that is timevarying, locationsensitive, and uniquely shared by a given transmitterreceiver pair. The complexity associated with a richly scattering environment implies that the shortterm fading process is inherently hard to predict and best modeled stochastically, with rapid decorrelation properties in space, time, and frequency. In this paper, we demonstrate how the channel state between a wireless transmitter and receiver can be used as the basis for building practical Secret Key generation protocols between two entities. We begin by presenting a scheme based on level crossings of the fading process, which is wellsuited for the Rayleigh and Rician fading models associated with a richly scattering environment. Our level crossing algorithm is simple, and incorporates a selfauthenticating mechanism to prevent adversarial manipulation of message exchanges during the protocol. Since the level crossing algorithm is best suited for fading processes that exhibit symmetry in their underlying distribution, we present a second and more powerful approach that is suited for more general channel state distributions. This second approach is motivated by observations from quantizing jointly Gaussian processes, but exploits empirical measurements to set quantization boundaries and a heuristic log likelihood ratio estimate to achieve an improved Secret Key generation rate. We validate both proposed protocols through experimentations using a customized 802.11a platform, and show for the typical WiFi channel that reliable Secret Key establishment can be accomplished at rates on the order of 10 b/s.

information theoretically Secret Key generation for fading wireless channels
arXiv: Cryptography and Security, 2009CoAuthors: Suhas Mathur, Alexander Reznik, Yogendra C Shah, Wade Trappe, Narayan B MandayamAbstract:The multipathrich wireless environment associated with typical wireless usage scenarios is characterized by a fading channel response that is timevarying, locationsensitive, and uniquely shared by a given transmitterreceiver pair. The complexity associated with a richly scattering environment implies that the shortterm fading process is inherently hard to predict and best modeled stochastically, with rapid decorrelation properties in space, time and frequency. In this paper, we demonstrate how the channel state between a wireless transmitter and receiver can be used as the basis for building practical Secret Key generation protocols between two entities. We begin by presenting a scheme based on level crossings of the fading process, which is wellsuited for the Rayleigh and Rician fading models associated with a richly scattering environment. Our level crossing algorithm is simple, and incorporates a selfauthenticating mechanism to prevent adversarial manipulation of message exchanges during the protocol. Since the level crossing algorithm is best suited for fading processes that exhibit symmetry in their underlying distribution, we present a second and more powerful approach that is suited for more general channel state distributions. This second approach is motivated by observations from quantizing jointly Gaussian processes, but exploits empirical measurements to set quantization boundaries and a heuristic log likelihood ratio estimate to achieve an improved Secret Key generation rate. We validate both proposed protocols through experimentations using a customized 802.11a platform, and show for the typical WiFi channel that reliable Secret Key establishment can be accomplished at rates on the order of 10 bits/second.

Secret Key generation for a pairwise independent network model
International Symposium on Information Theory, 2008CoAuthors: Sirin Nitinawarat, Prakash Narayan, Alexander Barg, Alexander ReznikAbstract:We investigate Secret Key generation for a ldquopairwise independent networkrdquo model in which every pair of terminals observes correlated sources which are independent of sources observed by all other pairs of terminals. The terminals are then allowed to communicate interactively in multiple rounds over a public noiseless channel of unlimited capacity, with all such communication being observed by all the terminals. The objective is to generate a Secret Key shared by a given subset of terminals at the largest rate possible. All the terminals cooperate in generating the Secret Key, with secrecy being required from an eavesdropper which has access to the public interterminal communication. We provide a (singleletter) formula for the secrecy capacity for this model, and show a natural connection between the problem of Secret Key generation and the combinatorial problem of maximal packing of Steiner trees in an associated multigraph. In particular, we show that the maximum number of Steiner tree packings in the multigraph is always a lower bound for the secrecy capacity. The bound is tight for the case when all the terminals seek to share a Secret Key; the mentioned connection yields an explicit capacityachieving algorithm. This algorithm, which can be executed in polynomial time, extracts a groupwide Secret Key of the optimum rate from the collection of optimum and mutually independent Secret Keys for pairs of terminals.
Holger Boche  One of the best experts on this subject based on the ideXlab platform.

on the computability of the Secret Key capacity under rate constraints
International Conference on Acoustics Speech and Signal Processing, 2019CoAuthors: Holger Boche, Rafael F Schaefer, Vincent H PoorAbstract:Secret Key generation refers to the problem of generating a common Secret Key without revealing any information about it to an eavesdropper. All users observe correlated components of a common source and can further use a ratelimited public channel for discussion which is open to eavesdroppers. This paper studies the Turing computability of the Secret Key capacity with a single ratelimited public forward transmission. Turing computability provides fundamental performance limits for today’s digital computers. It is shown that the Secret Key capacity under rate constraints is not Turing computable, and consequently there is no algorithm that can simulate or compute the Secret Key capacity, even if there are no limitations on computational complexity and computing power. On the other hand, if there are no rate constraints on the forward transmission, the Secret Key capacity is Turing computable. This shows that restricting the communication rate over the public channel transforms a Turing computable problem into a noncomputable problem. To the best of our knowledge, this is the first time that such a phenomenon has been observed.

Secret Key generation and convexity of the rate region using infinite compound sources
IEEE Transactions on Information Forensics and Security, 2018CoAuthors: Nima Tavangaran, Vincent H Poor, Rafael F Schaefer, Holger BocheAbstract:In SecretKey generation using a compound source, the actual statistics of the source are unknown to the participants. It is assumed rather that the actual source belongs to a set (compound set) which is known to the participants. The SecretKey generation protocol should guarantee in this case reliability and security of the generated SecretKey simultaneously for all elements of the compound set. In this paper, SecretKey generation based on a threeparty compound source is studied in which an eavesdropper’s side information is also taken into account and strong secrecy is guaranteed. At the same time, the public communication rate constraint between the legitimate users is part of the SecretKey generation protocol. In this setting, the achievable SecretKey rates for finite compound sources are first reformulated as a region of SecretKey rate versus communication rate constraint pairs. It is shown that this region is in general convex, even if the compound set is infinite. Based on this, the SecretKey capacity results are extended to be valid for arbitrary (possibly infinite) compound sources with a finite set of marginals. In this case, the SecretKey capacity is completely characterized as a function of the forward communication rate parameter between the legitimate users.

Secret Key capacity of infinite compound sources with communication rate constraint
International Conference on Communications, 2017CoAuthors: Nima Tavangaran, Holger Boche, Rafael F SchaeferAbstract:For SecretKey generation by using a compound source, the actual statistics of the source are unknown to the participants. It is assumed that the probability distribution of the source belongs to a set which is known to the participants. The SecretKey generation protocol should guarantee in this case the reliability and security of the generated SecretKey simultaneously for all possible source statistics which belong to this set. At the same time, the communication rate between the legitimate users should not exceed a given communication rate parameter. In this work, this problem is studied for the case where the set of source states is arbitrary (possibly infinite) and the set of marginals (transmitter's states) is finite. The SecretKey capacity is completely characterized as a function of the forward communication rate parameter between the legitimate users.