Untraceable Mobile Node Authentication in WSN

Mobility of sensor node in Wireless Sensor Networks (WSN) brings security issues such as re-authentication and tracing the node movement. However, current security researches on WSN are insufficient to support such environments since their designs only considered the static environments. In this paper, we propose the efficient node authentication and key exchange protocol that reduces the overhead in node re-authentication and also provides untraceability of mobile nodes. Compared with previous protocols, our protocol has only a third of communication and computational overhead. We expect our protocol to be the efficient solution that increases the lifetime of sensor network

Computer use at work is associated with self-reported depressive and anxiety disorder

Adjusted OR* of DAD considering the combined effect of computer use and occupational group, education, and job status. (DOC 61 kb

Throughput Fairness Enhancement Using Differentiated Channel Access in Heterogeneous Sensor Networks

Nowadays, with wireless sensor networks (WSNs) being widely applied to diverse applications, heterogeneous sensor networks (HSNs), which can simultaneously support multiple sensing tasks in a common sensor field, are being considered as the general form of WSN system deployment. In HSNs, each application generates data packets with a different size, thereby resulting in fairness issues in terms of the network performance. In this paper, we present the design and performance evaluation of a differentiated channel access scheme (abbreviated to DiffCA) to resolve the fairness problem in HSNs. DiffCA achieves fair performance among the application groups by providing each node with an additional backoff counter, whose value varies according to the size of the packets. A mathematical model based on the discrete time Markov chain is presented and is analyzed to measure the performance of DiffCA. The numerical results show that the performance degradation of disadvantaged application groups can be effectively compensated for by DiffCA. Simulation results are given to verify the accuracy of the numerical model

An Efficient and Secure Service Discovery Protocol for Ubiq- uitous Computing Environments

Recently, numerous service discovery protocols have been introduced in the open literature. Unfortunately, many of them did not consider security issues, and for those that did, many security and privacy problems still remain

An Efficient and Scalable Re-authentication Protocol over Wireless Sensor Network

Although wireless sensor network is considered as one of promising technologies for ubiquitous computing environment, more researches for re-authentication of mobile nodes in wireless sensor network are required due to user mobility, one of important properties in ubiquitous computing environment. As the citizens in a city can be mobile user in wireless sensor network and the resource of the sensor nodes is limited, scalability of re-authentication is important. In other words, re-authentication with less communication cost should be proposed. In this paper, we suggest an efficient method of membership verification for re-authentication of mobile node and show the performance analysis of our membership verification. Using this method, we propose an efficient and scalable re authentication protocol over wireless sensor network. Also, we provide performance and security analysis of our protocol

High Performance and Low Power Hardware Implementation for Cryptographic Hash Functions

Since hash functions are cryptography's most widely used primitives, efficient hardware implementation of hash functions is of critical importance. The proposed high performance hardware implementation of the hash functions used sponge construction which generates desired length digest, considering two key design metrics: throughput and power consumption. Firstly, this paper introduces unfolding transformation which increases the throughput of hash function and pipelining and parallelism design techniques which reduce the delay. Secondly, we propose a frequency trade-off technique which can give us a scope of frequency value for making a trade-off between low dynamic power consumption and high throughput. Finally, we use load-enable based clock gating scheme to eliminate wasted toggle rate of signals in the idle mode of hash encryption system. We demonstrated the proposed design techniques by using 45 nm CMOS technology at 10 MHz. The results show that we can achieve up to 47.97 times higher throughput, 6.31% delay reduction, and 13.65% dynamic power reduction

Digital Forensic Case Studies for In-Vehicle Infotainment Systems Using Android Auto and Apple CarPlay

Vehicle systems have been one of the fastest-growing fields in recent years. Vehicles are extremely helpful for understanding driver behaviors and have received significant attention from a forensic perspective. Extensive forensic research was previously conducted on on-board vehicle systems, such as an event data recorders, located in the electronic control unit or manufacturer-based infotainment systems. However, unlike previous vehicles that used only manufacturer-based infotainment systems, most vehicles today are equipped with infotainment systems such as Android Auto and Apple CarPlay. These in-vehicle infotainment (IVI) systems connect to mobile devices such as smartphones and tablets. The vehicle can periodically communicate with a smartphone and thus a network outside the vehicle. Drivers can use more services in their vehicles than ever before. Accordingly, an increasing number of diverse data are being stored in vehicles, with mobile devices connected to both the vehicle and the cloud. Such data include information that can be of significant help to investigators in solving problems during forensic investigations. Therefore, forensics of IVI systems such as Android Auto and Apple CarPlay are becoming increasingly important. We analyzed various forensic studies conducted on Android Auto and Apple CarPlay. Most of the research was mainly focused on mobile devices connected through a wired USB connection. The use of wireless-based IVI systems has recently been increasing. However, the analysis of Android Auto and Apple CarPlay from this point of view is insufficient. Therefore, we proposed a forensic methodology that fully considers such limitations. A forensic analysis was conducted on various IVI systems. We also developed an IVI system forensics tool that works based on the proposed methodology

A Brief Review of Gel Polymer Electrolytes Using In Situ Polymerization for Lithium-ion Polymer Batteries

Polymer electrolytes (PEs) have been thoroughly investigated due to their advantages that can prevent severe problems of Li-ion batteries, such as electrolyte leakage, flammability, and lithium dendrite growth to enhance thermal and electrochemical stabilities. Gel polymer electrolytes (GPEs) using in situ polymerization are typically prepared by thermal or UV curing methods by initially impregnating liquid precursors inside the electrode. The in situ method can resolve insufficient interfacial problems between electrode and electrolyte compared with the ex situ method, which could led to a poor cycle performance due to high interfacial resistance. In addition to the abovementioned advantage, it can enhance the form factor of bare cells since the precursor can be injected before polymerization prior to the solidification of the desired shapes. These suggest that gel polymer electrolytes prepared by in situ polymerization are a promising material for lithium-ion batteries