Future sensor networks require energy and bandwidth efficient designs to support the growing number of nodes. The security aspect is often neglected due to the extra computational burden imposed on the sensor nodes. In this article, we propose a secret key generation method for wireless sensor networks by using the physical layer features. This key generation method is based on the superposition property of wireless channels. The proposed method exploits the multiple access property of the wireless channel with simultaneous transmissions as in theanalog function computationtechnique to solve the latency and scarce bandwidth problems of highly populated dense networks. All nodes use the same time and frequency block to provide scalability that islinearly proportionalto the number of nodes. The proposed method also benefits from the network density to provide security against eavesdroppers that aim to sniff the secret key from the channel. The security of the proposed method against eavesdroppers is analytically studied. Moreover, their application in multiple layers is investigated. The presented results have shown that there is a tradeoff between the total power consumption and total used bandwidth for secret key generation. Lastly, the error probability of the generated keys due to thermal noise and channel estimation error is investigated with computer simulations and compared with broadcasting-based benchmark model.
Future sensor networks require energy and bandwidth efficient designs to support the growing number of nodes. The security aspect is often neglected due to the extra computational burden imposed on the sensor nodes. In this article, we propose a secret key generation method for wireless sensor networks by using the physical layer features. This key generation method is based on the superposition property of wireless channels. The proposed method exploits the multiple access property of the wireless channel with simultaneous transmissions as in theanalog function computationtechnique to solve the latency and scarce bandwidth problems of highly populated dense networks. All nodes use the same time and frequency block to provide scalability that islinearly proportionalto the number of nodes. The proposed method also benefits from the network density to provide security against eavesdroppers that aim to sniff the secret key from the channel. The security of the proposed method against eavesdroppers is analytically studied. Moreover, their application in multiple layers is investigated. The presented results have shown that there is a tradeoff between the total power consumption and total used bandwidth for secret key generation. Lastly, the error probability of the generated keys due to thermal noise and channel estimation error is investigated with computer simulations and compared with broadcasting-based benchmark model.
In this paper, we consider the problem of secret key generation for multiple parties. Multi-user networks usually require a trusted party to efficiently distribute keys to the legitimate users and this process is a weakness against eavesdroppers. With the help of the physical layer security techniques, users can securely decide on a secret key without a trusted party by exploiting the unique properties of the channel. In this context, we develop a physical layer group key generation scheme that is also based on the ideas of the analog function computation studies. We firstly consider the key generation as a function to be computed over the wireless channel and propose two novel methods depending on the users transmission capability (i.e. half-duplex and full-duplex transmissions). Secondly, we exploit the uniqueness of the prime integers in order to enable the simultaneous transmission of the users for key generation. As a result, our approach contributes to the scalability of the existing physical layer key generation algorithms since all users transmit simultaneously rather than using pairwise communications. We prove that our half-duplex network model reduces the required number of communications for group key generation down to a linear scale. Furthermore, the full-duplex network model reduces to a constant scale.
Wireless sensor networks (WSNs) are resource-constrained and highly vulnerable to eavesdropping due to their broadcast nature. Traditional symmetric key cryptography provides strong security but imposes excessive computational and energy demands on sensor nodes. Physical layer–based secret key generation (SKG) offers a lightweight alternative by exploiting channel reciprocity and randomness; however, existing methods are mostly limited to two-user scenarios and lack scalability in multi-user settings. This paper introduces two scalable multi-user SKG frameworks: a sequential method and a star topology-based method. In the sequential method, users cooperatively relay random signals to derive a shared key, while the star topology leverages a central node for signal aggregation and redistribution. A comparative analysis reveals trade-offs between the proposed methods. The sequential method is more computationally efficient but sensitive to node failures, while the star topology offers lower delay at the cost of requiring a fully connected central node. Analyses and simulations confirm both methods’ effectiveness in key mismatch probability, key generation rate, and key randomness validated by the National Institute of Standards and Technology test suite.
Wireless sensor networks are indispensable across various applications, from environmental surveillance to indus-trial automation, owing to their ability to collect and transmit data autonomously. However, due to the broadcast nature of wireless systems, these systems are vulnerable to eavesdropping attacks. Recently, channel-based secret key generation methods have been widely used in the literature. In these methods, Alice and Bob generate random signals and share these signals with each other. Then, using the secret key paired multiplication with the channel between them, a secret key is shared between legitimate users, while illegitimate nodes cannot access the key. However, these methods consider only two users. This paper proposes a novel method for multiple users. Extensive simulation proves the effectiveness of the proposed method. However, when the number of users increases, the performance of the proposed method decreases.
The applications of Wireless Sensor Networks (WSNs) are widespread in areas such as environmental monitoring, industrial automation, healthcare and smart infrastructures, where secure and reliable wireless communication is essential. The nature of a wireless channel, however, lends itself to the problem of eavesdropper-directed wireless sensor networking, interception and unauthorized access. This paper presents a secure physical layer communication system featuring the combination of channel estimator, physical layer key generator, artificial noise generator and adaptive power allocator to increase the confidentiality of physical layer communications and simultaneously achieve energy efficiency. A hybrid security mechanism is used, which takes advantage of the channel characteristics to create secret keys and to make the eavesdropper's signal reception worse by introducing controlled artificial noise. Key performance parameters considered for simulation-based evaluation are secrecy capacity, BER, PDR, Throughput, Energy consumption and Network lifetime. Results show that the secrecy capacity is 6.3 bps/Hz, the packet delivery ratio is 98.7%, the bit error rate is 10⁻⁶, and the network lifetime is 1675 rounds. The proposed framework is much more effective in terms of both communication security and energy efficiency than the traditional WSNs security schemes.
Wireless Sensor Networks (WSNs) are widely used in different disciplines, including transportation systems, agriculture field environment monitoring, healthcare systems, and industrial monitoring. The security challenge of the wireless communication link between sensor nodes is critical in WSNs. In this paper, we propose a new physical layer secret-key generation scheme for transportation security sensor network. The scheme is based on the cooperation of all the sensor nodes, thus avoiding the key distribution process, which increases the security of the system. Different passive and active attack models are analyzed in this paper. We also prove that when the cooperative node number is large enough, even when the eavesdropper is equipped with multiple antennas, the secret-key is still secure. Numerical results are performed to show the efficiency of the proposed scheme.
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.