A sensor network typically refers to a collection of sensor nodes equipped with sensing, communication and processing capabilities.It brings an opportunity to solve many difficult problems including real time monitoring, tracking, and controlling.While the applications of sensor networking become many and varied, security has always been one of the major concerns in real deployments.In this dissertation, we design physical primitives for secure communication in wireless sensor networks, and develop a wireless security framework to provide conventional security services.We investigate the feasibility of achieving perfect secrecy and information authenticity without shared secrets via two physical primitives: (i) cooperative jamming primitive, where we introduce a secure coding problem in which not only the sender but also the receiver participates in the coding.In essence, the receiver's role is to selectively jam the sender's transmission at the level of bits, bytes, or packets.We then design a class of secure codes, called "dialog codes", for diverse channel models and receiver models.(ii) spatial verification primitive, where we exploit the spatial signature induced by the radio communications of a node on its neighboring nodes, and design a spatial primitive that robustly and efficiently validates the authenticity of the source of messages.To address trust initialization, we propose a zero knowledge proof alternative that allows bootstrapping trust among individuals in a distributed way.
A sensor network typically refers to a collection of sensor nodes equipped with sensing, communication and processing capabilities.It brings an opportunity to solve many difficult problems including real time monitoring, tracking, and controlling.While the applications of sensor networking become many and varied, security has always been one of the major concerns in real deployments.In this dissertation, we design physical primitives for secure communication in wireless sensor networks, and develop a wireless security framework to provide conventional security services.We investigate the feasibility of achieving perfect secrecy and information authenticity without shared secrets via two physical primitives: (i) cooperative jamming primitive, where we introduce a secure coding problem in which not only the sender but also the receiver participates in the coding.In essence, the receiver's role is to selectively jam the sender's transmission at the level of bits, bytes, or packets.We then design a class of secure codes, called "dialog codes", for diverse channel models and receiver models.(ii) spatial verification primitive, where we exploit the spatial signature induced by the radio communications of a node on its neighboring nodes, and design a spatial primitive that robustly and efficiently validates the authenticity of the source of messages.To address trust initialization, we propose a zero knowledge proof alternative that allows bootstrapping trust among individuals in a distributed way.
The environment of wireless sensor networks (WSNs) makes the communication not only have the broadcast nature of wireless transmission, but also be limited to the low power and communication capability of sensor equipment. Both of them make it hard to ensure the confidentiality of communication. In this paper, we propose a cluster-based cooperative jamming scheme based on physical layer security for WSNs. The mathematical principle of the scheme is based on the design principle of code division multiple access. By using the orthogonality of orthogonal vectors, the legitimate receiver can effectively eliminate the noise, which is generated by the cooperative jamming nodes to disturb the eavesdropper. This scheme enables the legitimate receiver to ensure a strong communication confidentiality even if there is no location or channel advantage comparing with eavesdroppers. Through extensive simulations, the security performance of the proposed scheme is investigated in terms of secrecy rate.
The fast development of wireless networks, which are intrinsically exposed to eavesdropping, has created a growing concern for confidentiality. While classical cryptographic schemes require a key provided by the end-user, physical-layer security leverages the randomness of the physical communication medium as a source of secrecy. The main benefit of physical-layer security techniques is their relatively low cost and their ability to combine with any existing security mechanisms. This dissertation provides an analysis including the theoretical study of the two-way wiretap channel to obtain a better insight into how to design coding mechanisms, practical tests with experimental systems, and the design of actual codes. From a theoretical standpoint, the study confirms the benefits of combining several multi-user coding techniques including cooperative jamming, coded cooperative jamming and secret key generation. For these different mechanisms, the trade-off between reliability, secrecy and communication rate is clarified under a stringent strong secrecy metric. Regarding the design of practical codes, spatially coupled LDPC codes, which were originally designed for reliability, are modified to develop a coded cooperative jamming code. Finally, a proof-of-principle practical wireless system is provided to show how to implement a secret key generation system on experimental programmable radios. This testbed is then used to assess the realistic performance of such systems in terms of reliability, secrecy and rate.
Security functionality handled by higher layers of OSI model is a costly affair due to key management and complex mathematical encryption-decryption mechanisms in the scalable networks like wireless sensor networks (WSNs). WSN consists of resource constrained tiny sensor nodes for which battery is their lifetime. Physical layer security is the cost effective solution for such adhoc networks. The cooperative diversity mechanism makes use of the benefits of wireless sensor network scalability in terms of cooperative resource sharing in which multiple diversity channels are created which results into improved wireless connectivity. Cooperative jamming principle is used where the source transmits the encoded signal and at the same time relay transmits the weighted jamming signal to increase the equivocation of the eavesdropper. This work proposes a novel cooperative jamming mechanism for scalable networks like Wireless Sensor Networks (WSNs) which makes use of friendly interference to confuse the eavesdropper and increase its uncertainty about the source message. Channel fading is exploited to achieve perfect secrecy. The full communication link is built with the help of Information theoretic source and channel coding mechanisms. The whole idea is to make use of normally inactive relay nodes in the selective Decode and Forward cooperative communication and make them work as cooperative jamming sources to increase the equivocation of the eavesdropper. In this work, eavesdropper’s channel’s equivocation is compared with the main channel in terms of mutual information and secrecy capacity.
In this paper, we investigate physical layer network coding (PNC) and destination assisted cooperative jamming (DACJ) for physical layer security in wireless sensor networks, in which there is one source, one destination, a cluster of intermediate nodes, and multiple eavesdroppers. Under the PNC protocol, the considered two-hop wireless sensor network implements a complete transmission process in two phases. In the first phase, through sending a jamming signal from the destination and exploiting the PNC at the relay, the relay decodes the exclusive-OR (XOR) performed form of the source and the jamming message. Therefore, the jamming signal can degrade the wire-tap channels without hampering the legitimate channel. In the second phase, the relay transmits the re-encoded message to the destination while eavesdroppers are out of work as they cannot extract information from the signal. Thus, the proposed design can significantly improve the performance of secure wireless communications. Meanwhile, the proposed schemes select one optimal node from the intermediate nodes and give an optimal solution of power allocation to maximize secrecy capacity. Numerical simulation results show that the proposed schemes have a better and more stable secrecy performance than the conventional schemes at the same power consumption.
Wireless Sensor Networks (WSNs) are used for a wide range of things these days, from watching the environment to improving healthcare systems. But because these networks are used everywhere, they are also open to security risks like spying, data corruption, and node capture. It is very important to address these issues in order to protect the accuracy, privacy, and access of data being sent. Information-theoretic security looks like a good way to deal with these problems because it uses mathematical models to make sure that transmission in WSNs is safe and uses little energy. This essay goes into detail about information-theoretic security in WSNs. It gives a full rundown of the mathematical basics and real-world implications for getting strong security in places with limited resources. The idea of "secrecy capacity" is at the heart of this method. It measures the highest rate at which authorized nodes can communicate privately while preventing spying foes. Utilizing the chance that exists in wireless channels, encrypted keys can be generated without using shared secrets, making them resistant to attempts that try to steal them. Because sensor nodes only have a short power life, energy economy is very important in WSNs. Information-theoretic security methods, like physical layer security and joint communication, are designed to use as little energy as possible while still providing strong security. Nodes can work together to improve signal strength and fight channel fading using cooperative methods. This makes the network last longer without compromising security. This article also talks about the trade-offs between security, energy savings, and communication performance in WSNs. This helps us figure out how to make the best transfer schemes.
Physical layer security has been widely read up for decades to use physical layer qualities like unconventionality in wireless channels, motion toward clamor ratio hole, conscious sticking, and so on, to secure wireless correspondences. Secret rate is essential to define secure communication transmission rate in the presence of an eavesdropper. WSNs need secure communications since sensors send data to a fusion center. The most common cryptography techniques have been considered, but most of them are too computationally and energy-intensive for WSNs. Digital telecommunications networks sharing resources are called data networks. There are two networks: wired and wireless. Wireless networks are very popular due to its wireless setup and many household, business, and telecommunications networking applications. WSN were created when sensors detected physical or environmental conditions like pressure, temperature, or beam. WSN are elastic, easy, and straightforward. They grow because they're cheap and efficient. Wireless Sensor Networks have multiple sensor nodes scattered across a field that can measure, sense, compute, communicate, and send results to a base station. With increasing competence, security is also improving. Though the network was designed to be safe, hackers and attackers always find a way in and attack.