Since the emergence of Internet of Things (IoT) technology on the surface a few years ago, this IoT technology has been advancing. It has attracted the attention of cybercriminals. One of the cybercrime targets is the security of key management systems and their distribution schemes. This paper offers a solution to this issue by using a physical layer key generation (PLKG) scheme which utilizes the received signal strength indicator (RSSI) from a Long Range (LoRa) device as a key extraction source. The proposed scheme utilizes several methods. Polynomial fitting is used for the initial fitting process, 2-Ary quantization for conversion of RSSI to multibit, BCH to correct the difference in bits obtained between the two authorized users, privacy amplification for increased randomness, and AES-128 for encryption of sent messages. The expected outcome of this paper is that the scheme developed can generate keys with high approximate entropy and fulfills randomness requirements so that there is no need to distribute keys between authorized users. Testing the success of the scheme will be carried out in indoor and outdoor environments with static user positions. The test results show that the keys generated in all scenarios meet the randomness requirements with approximate entropy values above 0.01.
Since the emergence of Internet of Things (IoT) technology on the surface a few years ago, this IoT technology has been advancing. It has attracted the attention of cybercriminals. One of the cybercrime targets is the security of key management systems and their distribution schemes. This paper offers a solution to this issue by using a physical layer key generation (PLKG) scheme which utilizes the received signal strength indicator (RSSI) from a Long Range (LoRa) device as a key extraction source. The proposed scheme utilizes several methods. Polynomial fitting is used for the initial fitting process, 2-Ary quantization for conversion of RSSI to multibit, BCH to correct the difference in bits obtained between the two authorized users, privacy amplification for increased randomness, and AES-128 for encryption of sent messages. The expected outcome of this paper is that the scheme developed can generate keys with high approximate entropy and fulfills randomness requirements so that there is no need to distribute keys between authorized users. Testing the success of the scheme will be carried out in indoor and outdoor environments with static user positions. The test results show that the keys generated in all scenarios meet the randomness requirements with approximate entropy values above 0.01.
Physical-layer security (PLS) schemes use the randomness of the channel parameters, namely, channel state information (CSI) and received signal strength indicator (RSSI) to generate the secret keys. There has been limited work in PLS schemes in long-range (LoRa) wide-area networks (LoRaWANs) which hinder their widespread application. Limitations observed in existing studies include the requirement of high correlation between channel parameter measurements for secret key generation in the proposed schemes and the evaluation of the schemes has only been done in either fully indoor or outdoor environments. The real-world wireless sensor networks (WSNs) and LoRa use cases might not meet both requirements thus making the current PLS schemes inappropriate for these systems. By considering the limitations found in existing PLS schemes, this article proposes LoRA-LiSK, a practical and efficient shared secret key generation scheme for LoRa networks. Our proposed LoRa-LiSK scheme consists of several preprocessing techniques (timestamp matching, two sample Kolmogorov–Smirnov tests, and a Savitzky–Golay filter), multilevel quantization, information reconciliation using Bose–Chaudhuri–Hocquenghem (BCH) codes, and finally, privacy amplification using secure hash algorithm SHA-2. The LoRa-LiSK scheme is extensively evaluated on real WSN/IoT devices in practical application scenarios: 1) indoor to outdoor and 2) LoRa static and mobile outdoor links. It outperforms existing schemes by generating keys with channel parameter measurements of low correlation values (0.2–0.6), while still essentially achieving high key generation rates, and low key disagreement rates (10%–20%). The scheme updates a key in approximately 1 h using an application profile with high transmission rate compared to 3 h reported by existing works while still respecting the duty cycle regulation. It also incurs less communication overhead compared to the existing works.
The increasing use of Internet of Things (IoT) also make data security a very importance. Traditional cryptographic methods are often unsuitable for IoT due to limited processing power and memory capacity, creating a need for lightweight yet effective security solutions. Physical Layer Key Generation (PLKG) offers a promising approach by utilizing the unique characteristics of wireless communication channels to generate secret keys without overloaded system demands. This paper show a performance analysis of Group Secret Key Generation in outdoor environments. The challenges are interfrence, physical obstacles, and dynamic changes in the communication channel was also the part of this analysis. The test results show that group secret key generation achieved optimal performance in Scenario 2, which given a correlation coefficient of 63 %, indicating strong channel similarity between nodes and a bit retention rate of 97.9 % after quantization and error correction. Scenarios 1, 3, and 4 also show a good performance, with correlation coefficients of41%,14%, and 35 %, and corresponding bit retention rates of93.1%,90.9%, and 95.2 %, on each tests. All scenarios successfully met the entropy thresholds required for cryptographic applications, which include that randomness and security of the generated keys was confirmed.
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 at10km/hfor300meters, secondly both vehicle move at the same-direction at10km/hfor800meters, and lastly same as the second scenario but with different speed at20km/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.
Low-Power Wide Area Networks (LPWAN) has emerged as the dominant open specification in recent years due to its ability to offer affordable connectivity to the low-power devices distributed over large geographical areas. However, security issues have not been fully addressed in LPWAN specifications, especially, key distribution and key management. Physical layer key generation, which exploits wireless channel reciprocity and randomness to generate secure keys, has attracted considerable attention in recent years. In this paper, we exploit the physical layer key generation problem in LPWAN communication and present a distributed and lightweight key generation scheme for Long Range (LoRa) based network. It explores the shared randomness extracted from measured RSSI (Received Signal Strength Indicator) as consensus information to generate secure keys. To negotiate the RSSI signal as a bidirectional consistent key sequence, we propose a novel level-crossing quantization algorithm with an improved Cascade key agreement protocol to improve the key generation rate, as well as to avoid information leakage during transmission. We implement the proposed physical layer key generation scheme in a LoRa network prototype. Then we conduct extensive experiments in stationary and mobile indoor environments to evaluate the efficiency of the proposed key generation scheme. Experimental results show that its achievable key rate can reach 29.5% in stationary scenario and 35.5% in mobile scenario. Its key generation rate can exceed 1 bit/s with a lightweight implementation on the LoRa network prototype. For the 128-bit key sequence, it passes the the NIST suite of statistical tests.
Physical layer key generation that exploits reciprocity and randomness of wireless fading channels has attracted considerable attention in recent years. Despite much research efforts in this field, the problem of wireless key generation at long distance and low data rate remains unknown and has not been studied. In this paper, we conduct extensive experiments and analysis in real indoor and outdoor environments to explore the feasibility of wireless key generation for Long Range Wide Area Network (LoRaWAN). Based on the results, we present LoRa-Key, the first complete key establishment protocol for LoRaWAN by exploring the shared randomness extracted from measured Received Signal Strength Indicator (RSSI). LoRa-Key employs a number of signal processing techniques to improve key generation rate significantly. Experimental results show that LoRa-Key can achieve key establishment rates of 13 bit/s in stationary scenario and 21 bit/s in mobile scenario. To the best of our knowledge, this is the first work that studies key generation protocol for LoRaWAN.
Physical layer key generation that exploits reciprocity and randomness of wireless fading channels has attracted considerable attention in recent years. Despite much research efforts in this field, the problem of wireless key generation at long distance and low data rate remains unknown and has not been studied. In this paper, we conduct extensive experiments and analysis in real indoor and outdoor environments to explore the feasibility of wireless key generation for long range (LoRa)-based network. Our experimental results show that: 1) the low transmission rate will lead to low channel reciprocity which makes wireless key generation significantly challenging and 2) when the requirement of high reciprocity is fulfilled, two nodes can generate the same secret key even when they are far away from each other (a few kilometers). Building on the strengths of existing secret key extraction approaches, we present LoRa-Key, the first complete key establishment protocol for LoRa network by exploring the shared randomness extracted from measured received signal strength indicator. LoRa-Key employs a number of signal processing techniques to improve key generation rate significantly. Moreover, we propose a novel compressive sensing-based reconciliation framework to reduce mismatch rate. Experimental results show that LoRa-Key can achieve key establishment rates of 18 bit/s in stationary scenario and 31 bit/s in mobile scenario. To the best of our knowledge, this is the first work that studies key generation protocol for LoRa network.