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

IEEE International Conference on Acoustics Speech and Signal Processing

An effective key generation system using improved channel reciprocity

Junqing Zhang, Roger Woods, Alan Marshall, Trung Q. Duong

Published Apr 1, 2015• 29 citations
Publisher

Abstract

In physical layer security systems there is a clear need to exploit the radio link characteristics to automatically generate an encryption key between two end points. The success of the key generation depends on the channel reciprocity, which is impacted by the non-simultaneous measurements and the white nature of the noise. In this paper, an OFDM subcarriers' channel responses based key generation system with enhanced channel reciprocity is proposed. By theoretically modelling the OFDM subcarriers' channel responses, the channel reciprocity is modelled and analyzed. A low pass filter is accordingly designed to improve the channel reciprocity by suppressing the noise. This feature is essential in low SNR environments in order to reduce the risk of the failure of the information reconciliation phase during key generation. The simulation results show that the low pass filter improves the channel reciprocity, decreases the key disagreement, and effectively increases the success of the key generation.

DOI
10.1109/icassp.2015.7178266

Related papers

Efficient Key Generation by Exploiting Randomness From Channel Responses of Individual OFDM Subcarriers

Junqing Zhang, Alan Marshall, Roger Woods +1 more

Key generation from the randomness of wireless channels is a promising technique to establish a secret cryptographic key securely between legitimate users. This paper proposes a new approach to extract keys efficiently from the channel responses of individual orthogonal frequency-division multiplexing (OFDM) subcarriers. The efficiency is achieved by: 1) fully exploiting randomness from time and frequency domains and 2) improving the cross-correlation of the channel measurements. Through the theoretical modeling of the time and frequency autocorrelation relationship of the OFDM subcarrier's channel responses, we can obtain the optimal probing rate and use multiple uncorrelated subcarriers as random sources. We also study the effects of non-simultaneous measurements and noise on the cross-correlation of the channel measurements. We find that the cross-correlation is mainly impacted by noise effects in a slow fading channel and use a low-pass filter to reduce the key disagreement rate and extend the system's working signal-to-noise ratio range. The system is evaluated in terms of randomness, key generation rate, and key disagreement rate, verifying that it is feasible to extract randomness from both time and frequency domains of the OFDM subcarrier's channel responses.

IEEE Transactions on Communications•Apr 7, 2016•137 citations

Verification of Key Generation from Individual OFDM Subcarrier's Channel Response

Junqing Zhang, Roger Woods, Alan Marshall +1 more

This paper presents a key generation system derived from the channel response of individual subcarrier in orthogonal frequency-division multiplexing (OFDM) systems. Practical aspects of the security were investigated by implementing our key generation scheme on a wireless open-access research platform (WARP), which enables us to obtain channel estimation of individual OFDM subcarriers, a feature not currently available in most commercial wireless interface cards. Channel response of individual OFDM subcarrier is usually a wide sense stationary random process, which allows us to find the optimal probing period and maximize the key generation rate. The implementation requires cross layer design as it involves interaction between physical and MAC layer. We have experimentally verified the feasibility and principles of key generation, and also evaluated the performance of our system in terms of randomness, key generation rate and key disagreement rate, which proves that OFDM subcarrier's channel responses are valid for key generation.

IEEE Globecom Workshops (GC Wkshps)•Dec 1, 2015•21 citations

Channel reciprocity improvement of secret key generation with loop-back transmissions

Linning Peng, Guyue Li, Aiqun Hu

Secret key generation from wireless channel is an emerging technique to provide secure keys for message encryption. However, the measured channel state information (CSI) requires high reciprocity in order to obtain symmetric keys. In this paper, we propose a novel loop-back transmission scheme for time division duplex (TDD) systems, which is named as LB-TDD. The proposed LB-TDD scheme can effectively reduce the CSI non-reciprocity due to the hardware fingerprint interference and system synchronization offset. We initially discuss the benefits and optimizations of using LB-TDD for CSI reciprocity enhancement. After that, a secret key generation method based on orthogonal frequency division multiplexing (OFDM) probing signals is introduced. Finally, a channel model and a practical universal software radio peripheral (USRP) system is setup for both simulation and experimental verification. Evaluation results show that our proposed LB-TDD scheme can effectively eliminate CSI non-reciprocity for secret key generation.

IEEE International Conference on Communication Technology (ICCT)•Oct 1, 2017•3 citations

Key Generation Technique Based on Channel Characteristics for MIMO-OFDM Wireless Communication Systems

Dinh Van Linh, Van Yem Vu

Dynamic secret key generation from wireless channel characteristics is a promising technique for physical layer security. One of the important issues in this field is extending the secret key’s length while preserving its uniformity and randomness. This paper proposes a key generation method based on time-varying and the reciprocity of wireless channels for Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) wireless communication systems. In the proposed technique, the complex impulse response (CIR) of the estimated channel state information (CSI) is extracted, and a quantization algorithm is designed to convert the maximum peaks of the CIR into secret key bits. The effectiveness of the proposed key generation technique is assessed in terms of the randomness of the produced key bits with different key lengths by using a statistical test suite of the National Institute of Standards and Technology (NIST). The proposed technique is employed in the MIMO-OFDM systems with different modulation schemes through Additive White Gaussian Noise (AWGN) and Rayleigh channels. The simulation results show that the secret keys with various key lengths generated from the proposed technique for the MIMO-OFDM systems guarantee randomness. Moreover, the proposed CSI-based key generation technique provides better effectiveness in terms of security when compared to some existing techniques.

IEEE Access•Jan 1, 2023•27 citations

Scramble-Based Secret Key Generation Algorithm in Physical Layer Security

Dan Wang, Feng Chen, Yongtai Chen +2 more

As a new way to enhance wireless communication security, secret key generation based on physical layer channel characteristics has emerged. In this paper, we propose a novel secret key generation algorithm based on wireless channel characteristics for orthogonal frequency division multiplexing (OFDM) communication systems. The mean quantization algorithm is applied to quantize the real part and imaginary part of OFDM subcarriers, respectively, which can significantly increase the length of the generated secret key in the OFDM system. To reduce the consistency between the secret keys generated by the eavesdropper and the legitimate communication nodes, a processing method by taking the subcarrier phase as initialization of a scrambling code and scrambling the quantized result is proposed. The simulation and test results show that compared with the existing research, the proposed algorithm can improve the key generation rate (KGR), reduce the key mismatch rate (KMR) and complexity, maintain high randomness, and disturb the eavesdroppers.

Mobile Information Systems•Oct 4, 2022•1 citation

An Investigation of Using Loop-Back Mechanism for Channel Reciprocity Enhancement in Secret Key Generation

Linning Peng, Guyue Li, Junqing Zhang +3 more

Physical layer security key generation exploits unpredictable features from wireless channels to achieve high security, which requires high reciprocity in order to set up symmetric keys between two users. This paper investigates enhancing the channel reciprocity using a loop-back scheme with multiple frequency bands in time-division duplex (TDD) communication systems, in order to mitigate the effect of hardware fingerprint interference and synchronization offset. The scheme is evaluated to be robust to passive eavesdropping and active Man-in-the-Middle attack through both theoretical analyses and practical measurements. A secret key generation protocol is subsequently designed. The performance of the proposed secret key generation method is then evaluated through both numerical simulation and experiments. Results demonstrate that the proposed scheme can effectively mitigate non-reciprocity and outperforms the classical TDD scheme in both key disagreement rate and key generation rate.

IEEE Transactions on Mobile Computing•May 31, 2018•67 citations
In physical layer security systems there is a clear need to exploit the radio link characteristics to automatically generate an encryption key between two end points. The success of the key generation depends on the channel reciprocity, which is impacted by the non-simultaneous measurements and the white nature of the noise. In this paper, an OFDM subcarriers' channel responses based key generation system with enhanced channel reciprocity is proposed. By theoretically modelling the OFDM subcarriers' channel responses, the channel reciprocity is modelled and analyzed. A low pass filter is accordingly designed to improve the channel reciprocity by suppressing the noise. This feature is essential in low SNR environments in order to reduce the risk of the failure of the information reconciliation phase during key generation. The simulation results show that the low pass filter improves the channel reciprocity, decreases the key disagreement, and effectively increases the success of the key generation.
Key generation from the randomness of wireless channels is a promising technique to establish a secret cryptographic key securely between legitimate users. This paper proposes a new approach to extract keys efficiently from the channel responses of individual orthogonal frequency-division multiplexing (OFDM) subcarriers. The efficiency is achieved by: 1) fully exploiting randomness from time and frequency domains and 2) improving the cross-correlation of the channel measurements. Through the theoretical modeling of the time and frequency autocorrelation relationship of the OFDM subcarrier's channel responses, we can obtain the optimal probing rate and use multiple uncorrelated subcarriers as random sources. We also study the effects of non-simultaneous measurements and noise on the cross-correlation of the channel measurements. We find that the cross-correlation is mainly impacted by noise effects in a slow fading channel and use a low-pass filter to reduce the key disagreement rate and extend the system's working signal-to-noise ratio range. The system is evaluated in terms of randomness, key generation rate, and key disagreement rate, verifying that it is feasible to extract randomness from both time and frequency domains of the OFDM subcarrier's channel responses.
This paper presents a key generation system derived from the channel response of individual subcarrier in orthogonal frequency-division multiplexing (OFDM) systems. Practical aspects of the security were investigated by implementing our key generation scheme on a wireless open-access research platform (WARP), which enables us to obtain channel estimation of individual OFDM subcarriers, a feature not currently available in most commercial wireless interface cards. Channel response of individual OFDM subcarrier is usually a wide sense stationary random process, which allows us to find the optimal probing period and maximize the key generation rate. The implementation requires cross layer design as it involves interaction between physical and MAC layer. We have experimentally verified the feasibility and principles of key generation, and also evaluated the performance of our system in terms of randomness, key generation rate and key disagreement rate, which proves that OFDM subcarrier's channel responses are valid for key generation.
Secret key generation from wireless channel is an emerging technique to provide secure keys for message encryption. However, the measured channel state information (CSI) requires high reciprocity in order to obtain symmetric keys. In this paper, we propose a novel loop-back transmission scheme for time division duplex (TDD) systems, which is named as LB-TDD. The proposed LB-TDD scheme can effectively reduce the CSI non-reciprocity due to the hardware fingerprint interference and system synchronization offset. We initially discuss the benefits and optimizations of using LB-TDD for CSI reciprocity enhancement. After that, a secret key generation method based on orthogonal frequency division multiplexing (OFDM) probing signals is introduced. Finally, a channel model and a practical universal software radio peripheral (USRP) system is setup for both simulation and experimental verification. Evaluation results show that our proposed LB-TDD scheme can effectively eliminate CSI non-reciprocity for secret key generation.
Dynamic secret key generation from wireless channel characteristics is a promising technique for physical layer security. One of the important issues in this field is extending the secret key’s length while preserving its uniformity and randomness. This paper proposes a key generation method based on time-varying and the reciprocity of wireless channels for Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) wireless communication systems. In the proposed technique, the complex impulse response (CIR) of the estimated channel state information (CSI) is extracted, and a quantization algorithm is designed to convert the maximum peaks of the CIR into secret key bits. The effectiveness of the proposed key generation technique is assessed in terms of the randomness of the produced key bits with different key lengths by using a statistical test suite of the National Institute of Standards and Technology (NIST). The proposed technique is employed in the MIMO-OFDM systems with different modulation schemes through Additive White Gaussian Noise (AWGN) and Rayleigh channels. The simulation results show that the secret keys with various key lengths generated from the proposed technique for the MIMO-OFDM systems guarantee randomness. Moreover, the proposed CSI-based key generation technique provides better effectiveness in terms of security when compared to some existing techniques.
As a new way to enhance wireless communication security, secret key generation based on physical layer channel characteristics has emerged. In this paper, we propose a novel secret key generation algorithm based on wireless channel characteristics for orthogonal frequency division multiplexing (OFDM) communication systems. The mean quantization algorithm is applied to quantize the real part and imaginary part of OFDM subcarriers, respectively, which can significantly increase the length of the generated secret key in the OFDM system. To reduce the consistency between the secret keys generated by the eavesdropper and the legitimate communication nodes, a processing method by taking the subcarrier phase as initialization of a scrambling code and scrambling the quantized result is proposed. The simulation and test results show that compared with the existing research, the proposed algorithm can improve the key generation rate (KGR), reduce the key mismatch rate (KMR) and complexity, maintain high randomness, and disturb the eavesdroppers.
Physical layer security key generation exploits unpredictable features from wireless channels to achieve high security, which requires high reciprocity in order to set up symmetric keys between two users. This paper investigates enhancing the channel reciprocity using a loop-back scheme with multiple frequency bands in time-division duplex (TDD) communication systems, in order to mitigate the effect of hardware fingerprint interference and synchronization offset. The scheme is evaluated to be robust to passive eavesdropping and active Man-in-the-Middle attack through both theoretical analyses and practical measurements. A secret key generation protocol is subsequently designed. The performance of the proposed secret key generation method is then evaluated through both numerical simulation and experiments. Results demonstrate that the proposed scheme can effectively mitigate non-reciprocity and outperforms the classical TDD scheme in both key disagreement rate and key generation rate.