Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Wireless Telecommunications Symposium

Intelligent mechanisms for key generation from multipath wireless channels

Youssef El Hajj Shehadeh, Omar Alfandi, Kifah R. Tout, Dieter Hogrefe

Published Apr 1, 2011• 28 citations
Publisher

Abstract

The wireless communication channel has been found recently to have some interesting properties. In particular, it has been found that the multipath wireless channel can be leveraged for the purpose of key generation. In this paper, we investigate this property and propose an intelligent key generation method based on phase shifting and correction. Further, we discuss improvements of this approach and finally, we test our algorithm on a typical outdoor wireless channel. Our simulation results show that more than 90 bits can be generated from a single channel observation.

DOI
10.1109/wts.2011.5960848

Related papers

An Optimal Guard-Intervals Based Mechanism for Key Generation from Multipath Wireless Channels

Youssef El Hajj Shehadeh, Dieter Hogrefe

Recently, multipath in wireless channels has shown an interesting aspect. It has been found that wireless channels may provide a common reciprocal source of randomness for any two communicating nodes. This seems particularly interesting for secret key generation in wireless networks. In this paper, we consider the randomness property of wireless channels and present an intelligent algorithm for key generation. We analyze the multipath channel and derive optimal parameters enabling efficient key extraction leveraging the richness of a wireless environment. Finally, we test our algorithm in a typical outdoor wireless channel. Our simulation results show that more than 70 secret bits can be extracted from a single channel observation.

IFIP International Conference on New Technologies, Mobility and Security (NTMS)•Feb 1, 2011•30 citations

Towards robust key extraction from multipath wireless channels

Youssef El Hajj Shehadeh, Omar Alfandi, Dieter Hogrefe

This paper tackles the problem of generating shared secret keys based on the physical characteristics of the wireless channel. We propose intelligent quantization mechanisms for key generation, achieving high secret bits generation rate. Moreover, some practical issues affecting the performance of the key generation mechanism are deeply investigated. Mainly, we investigate the effects of delay and mobility on the performance and we enhance the key generation mechanism accordingly. As a result, this paper presents a framework towards robust key generation from multipath wireless channels.

Journal of Communications and Networks•Aug 1, 2012•38 citations

Secure wireless communications: Secret keys through multipath

A.M. Sayeed, Adrian Perrig

Secure wireless communications is a challenging problem due to the shared nature of the wireless medium. Most existing security protocols apply cryptographic techniques for bit scrambling at the application layer by exploiting a shared secret key between pairs of communicating nodes. However, more recent research argues that multipath propagation - a salient feature of wireless channels - provides a physical resource for secure communications. In this context, we propose a protocol that exploits the inherent randomness in multipath wireless channels for generating secret keys through channel estimation and quantization. Our approach is particularly attractive in wideband channels which exhibit a large number of statistically independent degrees of freedom (DoF), thereby enabling the generation of large, more-secure, keys. We show that the resulting keys are distinct for distinct pairwise links with a probability that increases exponentially with the key-size/channel DoF. We also characterize the probability that the two users sharing a common link generate the same key. This characterization is used to analyze the energy consumption in successful acquisition of a secret key by the two users. For a given key size, our results show that there is an optimum transmit power, and an optimum quantization strategy, that minimizes the energy consumption. The proposed approach to secret key generation through channel quantization also obviates the problem of key pre-distribution inherent to many existing cryptographic approaches.

IEEE International Conference on Acoustics Speech and Signal Processing•Mar 1, 2008•240 citations

Fast and scalable secret key generation exploiting channel phase randomness in wireless networks

Qian Wang, Hai Su, Kui Ren +1 more

Recently, there has been great interest in physical layer security techniques that exploit the randomness of wireless channels for securely extracting cryptographic keys. Several interesting approaches have been developed and demonstrated for their feasibility. The state-of-the-art, however, still has much room for improving their practicality. This is because i) the key bit generation rate supported by most existing approaches is very low which significantly limits their practical usage given the intermittent connectivity in mobile environments; ii) existing approaches suffer from the scalability and flexibility issues, i.e., they cannot be directly extended to support efficient group key generation and do not suit for static environments. With these observations in mind, we present a new secret key generation approach that utilizes the uniformly distributed phase information of channel responses to extract shared cryptographic keys under narrowband multipath fading models. The proposed approach enjoys a high key bit generation rate due to its efficient introduction of multiple randomized phase information within a single coherence time interval as the keying sources. The proposed approach also provides scalability and flexibility because it relies only on the transmission of periodical extensions of unmodulated sinusoidal beacons, which allows effective accumulation of channel phases across multiple nodes. The proposed scheme is thoroughly evaluated through both analytical and simulation studies. Compared to existing work that focus on pairwise key generation, our approach is highly scalable and can improve the analytical key bit generation rate by a couple of orders of magnitude.

IEEE Conference on Computer Communications (INFOCOM)•Apr 1, 2011•255 citations

Secret key generation exploiting channel characteristics in wireless communications

Kui Ren, Hai Su, Qian Wang

Due to the broadcast nature of wireless channels, wireless communication is vulnerable to eavesdropping, message modification, and node impersonation. Securing the wireless communication requires the shared secret keys between the communicating entities. Traditional security schemes rely on public key infrastructures and cryptographic algorithms to manage secret keys. Recently, many physical-layer-based methods have been proposed as alternative solutions for key generation in wireless networks. These methods exploit the inherent randomness of the wireless fading channel to generate secret keys while providing information-theoretical security without intensive cryptographic computations. This article provides an overview of the existing PHY-based key generation schemes exploiting the randomness of the wireless channels. Specifically, we first introduce the fundamental and general framework of the PHY-based key generation schemes and then categorize them into two classes: received-signal-strength-based and channel- phase-based protocols. Finally, we present a performance comparison of them in terms of key disagreement probability, key generation rate, key bit randomness, scalability, and implementation issues.

IEEE Wireless Communications•Aug 1, 2011•262 citations

Analisys of frequency-correlation properties of multipath channel for encyprion key generation using samples of differential phase

Сулимов Амир Ильдарович, Oleg N. Sherstyukov, A. V. Karpov

Wireless Key Generation exploits randomness of fast fading of a multipath radio channel to create identical copies of a shared encryption key at two communication nodes. A promising way for creating a highly secure key is use of samples of differential phase, which allows to overcome short-term instability of frequency standards and to make key generation devices smaller. This study examines frequency-correlation properties of the multipath channel to justify a feasibility of encryption keys generation with the differential phase method. By computer simulation, frequency autocorrelation functions of the envelope and carrier phase of a multipath radio signal are obtained, and estimates of the channel coherence bandwidth are made for a typical urban propagation environment. For random variations of the differential phase of a two-sine probe signal, a probability distribution is analyzed, its uniformity tests are done, and estimates of Shannon entropy at various frequency separations of the two probing tones are made. An effect of the line-of-sight wave and the number of multipaths on the channel frequency-correlation function and on probabilistic properties of the differential phase is considered.

Moscow Workshop on Electronic and Networking Technologies (MWENT)•Mar 1, 2018•1 citation
The wireless communication channel has been found recently to have some interesting properties. In particular, it has been found that the multipath wireless channel can be leveraged for the purpose of key generation. In this paper, we investigate this property and propose an intelligent key generation method based on phase shifting and correction. Further, we discuss improvements of this approach and finally, we test our algorithm on a typical outdoor wireless channel. Our simulation results show that more than 90 bits can be generated from a single channel observation.
Recently, multipath in wireless channels has shown an interesting aspect. It has been found that wireless channels may provide a common reciprocal source of randomness for any two communicating nodes. This seems particularly interesting for secret key generation in wireless networks. In this paper, we consider the randomness property of wireless channels and present an intelligent algorithm for key generation. We analyze the multipath channel and derive optimal parameters enabling efficient key extraction leveraging the richness of a wireless environment. Finally, we test our algorithm in a typical outdoor wireless channel. Our simulation results show that more than 70 secret bits can be extracted from a single channel observation.
This paper tackles the problem of generating shared secret keys based on the physical characteristics of the wireless channel. We propose intelligent quantization mechanisms for key generation, achieving high secret bits generation rate. Moreover, some practical issues affecting the performance of the key generation mechanism are deeply investigated. Mainly, we investigate the effects of delay and mobility on the performance and we enhance the key generation mechanism accordingly. As a result, this paper presents a framework towards robust key generation from multipath wireless channels.
Secure wireless communications is a challenging problem due to the shared nature of the wireless medium. Most existing security protocols apply cryptographic techniques for bit scrambling at the application layer by exploiting a shared secret key between pairs of communicating nodes. However, more recent research argues that multipath propagation - a salient feature of wireless channels - provides a physical resource for secure communications. In this context, we propose a protocol that exploits the inherent randomness in multipath wireless channels for generating secret keys through channel estimation and quantization. Our approach is particularly attractive in wideband channels which exhibit a large number of statistically independent degrees of freedom (DoF), thereby enabling the generation of large, more-secure, keys. We show that the resulting keys are distinct for distinct pairwise links with a probability that increases exponentially with the key-size/channel DoF. We also characterize the probability that the two users sharing a common link generate the same key. This characterization is used to analyze the energy consumption in successful acquisition of a secret key by the two users. For a given key size, our results show that there is an optimum transmit power, and an optimum quantization strategy, that minimizes the energy consumption. The proposed approach to secret key generation through channel quantization also obviates the problem of key pre-distribution inherent to many existing cryptographic approaches.
Recently, there has been great interest in physical layer security techniques that exploit the randomness of wireless channels for securely extracting cryptographic keys. Several interesting approaches have been developed and demonstrated for their feasibility. The state-of-the-art, however, still has much room for improving their practicality. This is because i) the key bit generation rate supported by most existing approaches is very low which significantly limits their practical usage given the intermittent connectivity in mobile environments; ii) existing approaches suffer from the scalability and flexibility issues, i.e., they cannot be directly extended to support efficient group key generation and do not suit for static environments. With these observations in mind, we present a new secret key generation approach that utilizes the uniformly distributed phase information of channel responses to extract shared cryptographic keys under narrowband multipath fading models. The proposed approach enjoys a high key bit generation rate due to its efficient introduction of multiple randomized phase information within a single coherence time interval as the keying sources. The proposed approach also provides scalability and flexibility because it relies only on the transmission of periodical extensions of unmodulated sinusoidal beacons, which allows effective accumulation of channel phases across multiple nodes. The proposed scheme is thoroughly evaluated through both analytical and simulation studies. Compared to existing work that focus on pairwise key generation, our approach is highly scalable and can improve the analytical key bit generation rate by a couple of orders of magnitude.
Due to the broadcast nature of wireless channels, wireless communication is vulnerable to eavesdropping, message modification, and node impersonation. Securing the wireless communication requires the shared secret keys between the communicating entities. Traditional security schemes rely on public key infrastructures and cryptographic algorithms to manage secret keys. Recently, many physical-layer-based methods have been proposed as alternative solutions for key generation in wireless networks. These methods exploit the inherent randomness of the wireless fading channel to generate secret keys while providing information-theoretical security without intensive cryptographic computations. This article provides an overview of the existing PHY-based key generation schemes exploiting the randomness of the wireless channels. Specifically, we first introduce the fundamental and general framework of the PHY-based key generation schemes and then categorize them into two classes: received-signal-strength-based and channel- phase-based protocols. Finally, we present a performance comparison of them in terms of key disagreement probability, key generation rate, key bit randomness, scalability, and implementation issues.
Wireless Key Generation exploits randomness of fast fading of a multipath radio channel to create identical copies of a shared encryption key at two communication nodes. A promising way for creating a highly secure key is use of samples of differential phase, which allows to overcome short-term instability of frequency standards and to make key generation devices smaller. This study examines frequency-correlation properties of the multipath channel to justify a feasibility of encryption keys generation with the differential phase method. By computer simulation, frequency autocorrelation functions of the envelope and carrier phase of a multipath radio signal are obtained, and estimates of the channel coherence bandwidth are made for a typical urban propagation environment. For random variations of the differential phase of a two-sine probe signal, a probability distribution is analyzed, its uniformity tests are done, and estimates of Shannon entropy at various frequency separations of the two probing tones are made. An effect of the line-of-sight wave and the number of multipaths on the channel frequency-correlation function and on probabilistic properties of the differential phase is considered.