We address secure secret key distribution in wireless communication systems. There is the secrecy capacity concept that it can distribute information which the third parties can not eavesdrop because of the noise over the distribution channel. Then, we address secure secret key distribution in wireless communication systems using secrecy capacity concept. Wireless channel is noisier compared with wired channel. Specifically, we investigate about wiretap channel coding that it can implement in the existing wireless LAN systems. We have investigated the coding parameters and the conditions that it can implement.
We address secure secret key distribution in wireless communication systems. There is the secrecy capacity concept that it can distribute information which the third parties can not eavesdrop because of the noise over the distribution channel. Then, we address secure secret key distribution in wireless communication systems using secrecy capacity concept. Wireless channel is noisier compared with wired channel. Specifically, we investigate about wiretap channel coding that it can implement in the existing wireless LAN systems. We have investigated the coding parameters and the conditions that it can implement.
Wire-tap channel coding allows information-theoretically secure communication between legitimate sender and receiver in presence of an eavesdropper Eve, whose channel is subject to noise. A secrecy capacity for their communication is equal to capacity of the channel connecting them, minus capacity of Eve's channel, when the channels are assumed independent and affected by additive white Gaussian noise. In order to increase the secrecy capacity, we propose to employ a coding scheme using matched filter. The legitimate parties are assumed to share a pre-shared key of the matched filter, secretly from Eve. Hereby, the legitimate parties can use it to increase the capacity of their channel, while Eve cannot. We propose to apply this scheme to indoor wireless communication over IEEE 802.11 wireless LAN, analyze advantages of our construction and discuss an appropriate selection of coding scheme fitting the IEEE 802.11 protocol specification.
We investigate an approach to physical-layer security based on the premise that the coding mechanism for secrecy over noisy channels is fundamentally tied to the notion of resolvability. Instead of considering capacity-based constructions, which associate to each message a sub-code whose rate approaches the capacity of the eavesdropper’s channel, we consider resolvability-based constructions, which associate to each message a sub-code whose rate is beyond the resolvability of the eavesdropper’s channel. We provide evidence that resolvability is a more powerful and perhaps more fundamental coding mechanism for secrecy by developing results that hold for strong secrecy metrics and arbitrary channels. Specifically, we show that, at least for binary symmetric wiretap channels, random capacity-based constructions fail to approach the strong secrecy capacity while resolvability-based constructions achieve it. We then obtain the secrecy-capacity region of arbitrary broadcast channels with confidential messages and a cost constraint for strong secrecy metrics, which generalizes existing results. Finally, we specialize our results to study the secrecy capacity of wireless channels with perfect channel state information, compound and mixed channels, as well as the secret-key capacity of source models for secret-key agreement. By tying secrecy to resolvability, we obtain achievable rates for stronger secrecy metrics and with simpler proofs than previously derived. Index Terms information-theoretic security, wiretap channel, secret-key agreement, information-spectrum, resolv-ability, wireless channels.
Ensuring data privacy of wireless communication systems has been a challenging problem for various reasons. The simplicity of eavesdropping on wireless transmissions makes the barrier to entry lower for wireless than for wired systems. Due to size and power constraints, wireless systems are sometimes unable to implement the complex cryptographic algorithms that can ensure the privacy of their data, leaving them with weaker schemes that are more easily exploited. However, the wireless security problem has one distinct advantage over the wired problem in that the channel seen by the eavesdropper is not usually correlated with the channel seen by the intended receiver. Recent research in the community has suggested that the randomness inherent in the wireless channel may be exploited to create secret keys dynamically, making simple wireless cryptographic schemes extremely strong and in some applications providing perfect secrecy. In this paper, we present some information theory bounds on key lengths for various wireless channel models and discuss the impact such physical channel-derived dynamic re-keying would have on various applications. We also present some thoughts on proving out the concepts in actual systems.
In Chapter 3, we considered the transmission of information over a noisy broadcast channel subject to reliability and security constraints; we showed that appropriate coding schemes can exploit the presence of noise to confuse the eavesdropper and guarantee some amount of information-theoretic security. It is important to note that the wiretap channel model assumes that all communications occur over the channel, hence communications are inherently rate-limited and one-way. Consequently, the results obtained do not fully capture the role of noise for secrecy; in particular, for situations in which the secrecy capacity is zero, it is not entirely clear whether this stems from the lack of any “physical advantage” over the eavesdropper or the restrictions imposed on the communication schemes. The objective of this chapter is to study more precisely the fundamental role of noise in information-theoretic security. Instead of studying how we can communicate messages securely over a noisy channel, we now analyze how much secrecy we can extract from the noise itself in the form of a secret key. Specifically, we assume that the legitimate parties and the eavesdropper observe the realizations of correlated random variables and that the legitimate parties attempt to agree on a secret key unknown to the eavesdropper. To isolate the role played by noise, we remove restrictions on communication schemes and we assume that the legitimate parties can distill their key by communicating over a two-way, public, noiseless , and authenticated channel at no cost.
The location-specific channel state information can be exploited to generate secret keys for wireless system services, In the multipath wireless environment. Its secrecy capacity was usually studied with the wiretap channel model. This paper proposes a side channel model which is even more threatening to the security of the physical layer randomness based secret keys. We present the information-theoretic analysis of the side channel model, and compare it with the wire-tap model. The analysis indicates that the secret key capacity of the side-channel will be lower than that of the wire-tap channel, especially with a fading scenario. We conduct MATLAB simulation of physical layer randomness based key generation and SPICE simulation of key extraction to observe the side channel leakage of the circuit. The simulation results confirm the consistency of the key bits, thus verifying the feasibility of our proposed side-channel attack scheme against the physical layer security.
We analyze physical-layer security based on the premise that the coding mechanism for secrecy over noisy channels is tied to the notion of channel resolvability. Instead of considering capacity-based constructions, which associate to each message a sub-code that operates just below the capacity of the eavesdropper's channel, we consider channel-resolvability-based constructions, which associate to each message a sub-code that operates just above the resolvability of the eavesdropper's channel. Building upon the work of Csiszar and Hayashi, we provide further evidence that channel resolvability is a powerful and versatile coding mechanism for secrecy by developing results that hold for strong secrecy metrics and arbitrary channels. Specifically, we show that at least for symmetric wiretap channels, random capacity-based constructions fail to achieve the strong secrecy capacity while channel-resolvability-based constructions achieve it. We then leverage channel resolvability to establish the secrecy-capacity region of arbitrary broadcast channels with confidential messages and a cost constraint for strong secrecy metrics. Finally, we specialize our results to study the secrecy capacity of wireless channels with perfect channel state information, mixed channels and compound channels with receiver Channel State Information (CSI), as well as the secret-key capacity of source models for secret-key agreement. By tying secrecy to channel resolvability, we obtain achievable rates for strong secrecy metrics with simple proofs.