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 Transactions on Mobile Computing

Toward a Practical Key Generation System for V2X Communications

Hua Fu, Linning Peng, Junqing Zhang, Ming Liu, Xudong Chen, Aiqun Hu

Published Dec 5, 2025• 1 citation
Publisher

Abstract

The vehicle to everything (V2X) serves as a crucial foundation for future intelligent transportation systems. Security concerns within the V2X have garnered significant attention and key generation from wireless channels have emerged as a promising technique. However, applying key generation to V2X is quite challenging because the fast moving vehicles result in very small coherence time and impact channel measurements correlation. This paper designed a practical V2X key generation by enhancing channel state information (CSI) reciprocity and carried out extensive experimental evaluation. In particular, the designed key generation consists of channel probing, CSI preprocessing, CSI compensation and key establishment. In the channel probing, we deliberately reduced the time delay between uplink and downlink transmissions, to allow almost simultaneous measurements. We then carefully designed CSI preprocessing to remove hardware carrier leakage and eliminate noise effects. Furthermore, we devised CSI compensation by using interpolation or deep learning prediction to further improve the reciprocity. Finally, key establishment converted the measured CSI into binary sequences and reconcile on a common key via low-density parity-check (LDPC) code. We adopted universal software radio peripheral (USRP) X310 platforms for channel measurements and implemented the above algorithms. We carried out extensive experiments in real-road environments with various vehicle speeds. These carefully designed algorithms enabled our system working robustly even in high mobility scenarios, e.g., 40 km/h. Experimental results demonstrated common and random key can be generated with a key block error rate (BER) less than 0.1.

DOI
10.1109/tmc.2025.3640580

Related papers

Channel State Information-Based Cryptographic Key Generation for Intelligent Transportation Systems

Soheyb Ribouh, Kelvin Huy-Trung Phan, Arnav Vaibhav Malawade +3 more

Due to the sensitivity of the information exchanged in Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) communication, generating secret keys is critical to secure these communications. As nature is open access, distributed keys are more vulnerable to attacks in the vehicular environment. Physical layer key generation methods using wireless channel characteristics show promise in preventing such attacks, generating keys independently, and removing the need for distribution. In this paper, we present a novel key generation approach in a real vehicular environment based on Channel State Information (CSI), including a new algorithm for key bit extraction. We implemented our algorithm using USRP B210 Software-Defined Radios (SDR) and the industry-standard V2X communication protocol: IEEE 802.11p. The proposed key generation protocol uses the CSI values of each sub-carrier as a source of randomness, from which bits are extracted using a new QAM demodulator quantizer (QAM-Dem-Quan). We compared our technique to state-of-the-art Received Signal Strength (RSS)-based approaches, and show that our method achieves better performance. Moreover, we reached a min-entropy of approximately 70% for the generated keys and a key generation rate of less than$150~\mu \text{s}$/key for key lengths ranging from 16 to 128 bits.

IEEE Transactions on Intelligent Transportation Systems•Jul 8, 2020•54 citations

Implementation of V2V Communication Security on LoRa-Based Physical Layer Key Generation

Ezekiel Furqon Patongai, Mike Yuliana, Amang Sudarsono

With the rise of connected vehicular networks, Vehicle-to-Vehicle (V2V) communication has become a fundamental enabler for intelligent transportation systems. However, the open nature of wireless channels introduces risks such as eavesdropping and key compromise. To address these issues, we propose a secure V2V communication scheme based on Physical Layer Key Generation (PLKG) using LoRa technology. The proposed system utilizes Received Signal Strength Indicator (RSSI) measurements between two moving vehicles as the entropy source. To improve the channel correlation, a Savitzky-Golay filter is applied as a preprocessing step. Adaptive multibit quantization is then used to convert the RSSI into binary sequences, followed by the Cascade algorithm for error reconciliation. To enhance randomness, privacy amplification is applied using universal hashing and SHA-1. Finally, the generated key is used for AES-128 encryption. The system is implemented on Raspberry Pi 4B using AcSiP EK-S76SXB and RAK2245 LoRa modules. Experimental validation was conducted in three movement scenarios firstly both vehicle move from opposite-direction at$\mathbf{1 0 ~ k m} / \mathbf{h}$for$\mathbf{3 0 0}$meters, secondly both vehicle move at the same-direction at$\mathbf{1 0 ~ k m} / \mathbf{h}$for$\mathbf{8 0 0}$meters, and lastly same as the second scenario but with different speed at$20 ~\text{km} / \mathrm{h}$. Results shown that the system achieves a reliable key generation rate (KGR) of up to 176075.73 bit/s while maintaining low computation time, demonstrating its feasibility for secure real-time V2V communication.

International Electronics Symposium (IES)•Aug 5, 2025•0 citations

Physical Layer Key Generation from Wireless Channels with Non-ideal Channel Reciprocity: A Deep Learning Based Approach

Cheng Feng, Li Sun

Physical layer encryption is a promising solution to provide transmission security for Internet-of-Things (IoT). To realize physical layer encryption, channel state information (CSI) as a random source to generate secret keys should be exploited. The reciprocity of wireless channel between legitimate communication nodes which is typically assumed for time division duplex (TDD) systems, is of critical importance to ensure the consistency in generated keys at two nodes. However, in practical TDD systems, due to the asynchronous measurement of CSI, the receiver noise and the the difference in hardware, etc., the reciprocity of channel measurements between legitimate parties is hard to be guaranteed, which makes physical layer key generation approach infeasible. To address this issue, we propose a wireless key generation scheme based on deep learning techniques. Firstly, a feature extraction network, which consists of two auto-encoders trained jointly, is developed to extract the common feature from the different yet correlated channel observations at two legitimate nodes, which will be used as the source to generate keys. Then a quantizer with an adaptive guard band width is devised to output a binary secret-key sequence from the feature vector. Numerical results show that the proposed scheme achieves remarkable improvement in terms of key disagreement rate (KDR) and key generation rate (KGR) compared existing counterparts in the literature.

IEEE Vehicular Technology Conference•Jun 1, 2022•13 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

A Lightweight and Efficient Physical Layer Key Generation Mechanism for MANETs

Xiaomiao Gao, Wenjie Du, Weijiang Liu +2 more

Due to the reciprocity of wireless channels, the communication parties can directly extract the shared key from channel. This solution were verified through several schemes. However, in real situations, channel sampling of legitimate transceivers might be impacted by noises and other interferences, which makes the channel states obtained by initiator and responder might be obvious different. The efficiency and even availability of physical layer key generation are thus reduced. In this paper, we propose a lightweight and efficient physical layer key generation scheme, which extract shared secret keys from channel state information (CSI). To improve the key generation process, the discrete cosine transform (DCT) is employed to reduce differences of channel states of legitimate transceivers. Then, these outputs are quantified and encoded through multi-bit adaptive quantization(MAQ) quantizer and gray code to generate binary bit sequence, which can greatly reduce the bit error rate. Moreover, the low density parity check (LDPC) code and universal hashing functions are used to achieve information reconciliation and privacy amplifification. By adding preprocessing methods in the key generation process and using the rich information of CSI, the security of communications can be increased on the basis of improving the key generation rate. To evaluate this scheme, a number of experiments in various real environments are conducted. The experimental results show that the proposed scheme can effificiently generate shared secret keys for nodes and protect their communication.

IEEE International Conference on Computer and Communications (ICCC)•Dec 11, 2020•5 citations

Efficient Key Extraction for Secure Vehicular Communication Through OTFS

Agnes Francis Kawoya, Hua Wang, Mohammed Salah Abood

Vehicular communication is delay sensitive and demands high security. However, the time for key establishment between node pairs is limited due to the unique features of fast-moving and high dynamics in Vehicular ad hoc networks (VANETs). Moreover, under high-mobility scenarios, the communication performance of Orthogonal Frequency Division Multiplexing (OFDM) signals degrades significantly, while Orthogonal Time Frequency Space (OTFS) signals maintains better performance. Towards this end, considering the time for key establishment, we propose an efficient physical layer secret key generation (PLSKG) scheme utilizing OTFS channel state information (CSI). First, we preprocess the estimated CSI with a moving average coding (MAC) algorithm to improve channel reciprocity. Next, we adopt a bidirectional difference quantization (BDQ) for increased key bit generation and propose a one-way reconciliation protocol to remove bit mismatch. Results from extensive simulations have verified that our scheme achieves random 0-b disagreement keys with a high key generation rate and reduced time for key establishment compared to other schemes.

IEEE Communications Letters•Jan 5, 2024•8 citations
The vehicle to everything (V2X) serves as a crucial foundation for future intelligent transportation systems. Security concerns within the V2X have garnered significant attention and key generation from wireless channels have emerged as a promising technique. However, applying key generation to V2X is quite challenging because the fast moving vehicles result in very small coherence time and impact channel measurements correlation. This paper designed a practical V2X key generation by enhancing channel state information (CSI) reciprocity and carried out extensive experimental evaluation. In particular, the designed key generation consists of channel probing, CSI preprocessing, CSI compensation and key establishment. In the channel probing, we deliberately reduced the time delay between uplink and downlink transmissions, to allow almost simultaneous measurements. We then carefully designed CSI preprocessing to remove hardware carrier leakage and eliminate noise effects. Furthermore, we devised CSI compensation by using interpolation or deep learning prediction to further improve the reciprocity. Finally, key establishment converted the measured CSI into binary sequences and reconcile on a common key via low-density parity-check (LDPC) code. We adopted universal software radio peripheral (USRP) X310 platforms for channel measurements and implemented the above algorithms. We carried out extensive experiments in real-road environments with various vehicle speeds. These carefully designed algorithms enabled our system working robustly even in high mobility scenarios, e.g., 40 km/h. Experimental results demonstrated common and random key can be generated with a key block error rate (BER) less than 0.1.
Due to the sensitivity of the information exchanged in Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) communication, generating secret keys is critical to secure these communications. As nature is open access, distributed keys are more vulnerable to attacks in the vehicular environment. Physical layer key generation methods using wireless channel characteristics show promise in preventing such attacks, generating keys independently, and removing the need for distribution. In this paper, we present a novel key generation approach in a real vehicular environment based on Channel State Information (CSI), including a new algorithm for key bit extraction. We implemented our algorithm using USRP B210 Software-Defined Radios (SDR) and the industry-standard V2X communication protocol: IEEE 802.11p. The proposed key generation protocol uses the CSI values of each sub-carrier as a source of randomness, from which bits are extracted using a new QAM demodulator quantizer (QAM-Dem-Quan). We compared our technique to state-of-the-art Received Signal Strength (RSS)-based approaches, and show that our method achieves better performance. Moreover, we reached a min-entropy of approximately 70% for the generated keys and a key generation rate of less than150 μs150~\mu \text{s}150 μs/key for key lengths ranging from 16 to 128 bits.
With the rise of connected vehicular networks, Vehicle-to-Vehicle (V2V) communication has become a fundamental enabler for intelligent transportation systems. However, the open nature of wireless channels introduces risks such as eavesdropping and key compromise. To address these issues, we propose a secure V2V communication scheme based on Physical Layer Key Generation (PLKG) using LoRa technology. The proposed system utilizes Received Signal Strength Indicator (RSSI) measurements between two moving vehicles as the entropy source. To improve the channel correlation, a Savitzky-Golay filter is applied as a preprocessing step. Adaptive multibit quantization is then used to convert the RSSI into binary sequences, followed by the Cascade algorithm for error reconciliation. To enhance randomness, privacy amplification is applied using universal hashing and SHA-1. Finally, the generated key is used for AES-128 encryption. The system is implemented on Raspberry Pi 4B using AcSiP EK-S76SXB and RAK2245 LoRa modules. Experimental validation was conducted in three movement scenarios firstly both vehicle move from opposite-direction at10 km/h\mathbf{1 0 ~ k m} / \mathbf{h}10 km/hfor300\mathbf{3 0 0}300meters, secondly both vehicle move at the same-direction at10 km/h\mathbf{1 0 ~ k m} / \mathbf{h}10 km/hfor800\mathbf{8 0 0}800meters, and lastly same as the second scenario but with different speed at20 km/h20 ~\text{km} / \mathrm{h}20 km/h. Results shown that the system achieves a reliable key generation rate (KGR) of up to 176075.73 bit/s while maintaining low computation time, demonstrating its feasibility for secure real-time V2V communication.
Physical layer encryption is a promising solution to provide transmission security for Internet-of-Things (IoT). To realize physical layer encryption, channel state information (CSI) as a random source to generate secret keys should be exploited. The reciprocity of wireless channel between legitimate communication nodes which is typically assumed for time division duplex (TDD) systems, is of critical importance to ensure the consistency in generated keys at two nodes. However, in practical TDD systems, due to the asynchronous measurement of CSI, the receiver noise and the the difference in hardware, etc., the reciprocity of channel measurements between legitimate parties is hard to be guaranteed, which makes physical layer key generation approach infeasible. To address this issue, we propose a wireless key generation scheme based on deep learning techniques. Firstly, a feature extraction network, which consists of two auto-encoders trained jointly, is developed to extract the common feature from the different yet correlated channel observations at two legitimate nodes, which will be used as the source to generate keys. Then a quantizer with an adaptive guard band width is devised to output a binary secret-key sequence from the feature vector. Numerical results show that the proposed scheme achieves remarkable improvement in terms of key disagreement rate (KDR) and key generation rate (KGR) compared existing counterparts in the literature.
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.
Due to the reciprocity of wireless channels, the communication parties can directly extract the shared key from channel. This solution were verified through several schemes. However, in real situations, channel sampling of legitimate transceivers might be impacted by noises and other interferences, which makes the channel states obtained by initiator and responder might be obvious different. The efficiency and even availability of physical layer key generation are thus reduced. In this paper, we propose a lightweight and efficient physical layer key generation scheme, which extract shared secret keys from channel state information (CSI). To improve the key generation process, the discrete cosine transform (DCT) is employed to reduce differences of channel states of legitimate transceivers. Then, these outputs are quantified and encoded through multi-bit adaptive quantization(MAQ) quantizer and gray code to generate binary bit sequence, which can greatly reduce the bit error rate. Moreover, the low density parity check (LDPC) code and universal hashing functions are used to achieve information reconciliation and privacy amplifification. By adding preprocessing methods in the key generation process and using the rich information of CSI, the security of communications can be increased on the basis of improving the key generation rate. To evaluate this scheme, a number of experiments in various real environments are conducted. The experimental results show that the proposed scheme can effificiently generate shared secret keys for nodes and protect their communication.
Vehicular communication is delay sensitive and demands high security. However, the time for key establishment between node pairs is limited due to the unique features of fast-moving and high dynamics in Vehicular ad hoc networks (VANETs). Moreover, under high-mobility scenarios, the communication performance of Orthogonal Frequency Division Multiplexing (OFDM) signals degrades significantly, while Orthogonal Time Frequency Space (OTFS) signals maintains better performance. Towards this end, considering the time for key establishment, we propose an efficient physical layer secret key generation (PLSKG) scheme utilizing OTFS channel state information (CSI). First, we preprocess the estimated CSI with a moving average coding (MAC) algorithm to improve channel reciprocity. Next, we adopt a bidirectional difference quantization (BDQ) for increased key bit generation and propose a one-way reconciliation protocol to remove bit mismatch. Results from extensive simulations have verified that our scheme achieves random 0-b disagreement keys with a high key generation rate and reduced time for key establishment compared to other schemes.