The Meeting of Acquaintances: A Cost-efficient Authentication Scheme for Light-weight Objects with Transient Trust Level and Plurality Approach

Wireless sensor networks consist of a large number of distributed sensor nodes so that potential risks are becoming more and more unpredictable. The new entrants pose the potential risks when they move into the secure zone. To build a door wall that provides safe and secured for the system, many recent research works applied the initial authentication process. However, the majority of the previous articles only focused on the Central Authority (CA) since this leads to an increase in the computation cost and energy consumption for the specific cases on the Internet of Things (IoT). Hence, in this article, we will lessen the importance of these third parties through proposing an enhanced authentication mechanism that includes key management and evaluation based on the past interactions to assist the objects joining a secured area without any nearby CA. We refer to a mobility dataset from CRAWDAD collected at the University Politehnica of Bucharest and rebuild into a new random dataset larger than the old one. The new one is an input for a simulated authenticating algorithm to observe the communication cost and resource usage of devices. Our proposal helps the authenticating flexible, being strict with unknown devices into the secured zone. The threshold of maximum friends can modify based on the optimization of the symmetric-key algorithm to diminish communication costs (our experimental results compare to previous schemes less than 2000 bits) and raise flexibility in resource-constrained environments.Comment: 27 page

Fly-By-Wireless for Next Generation Aircraft: Challenges and Potential solutions

”Fly-By-Wireless” paradigm based on wireless connectivity in aircraft has the potential to improve efficiency and flexibility, while reducing weight, fuel consumption and maintenance costs. In this paper, first, the opportunities and challenges for wireless technologies in safety-critical avionics context are discussed. Then, the assessment of such technologies versus avionics requirements is provided in order to select the most appropriate one for a wireless aircraft application. As a result, the design of a Wireless Avionics Network based on Ultra WideBand technology is investigated, considering the issues of determinism, reliability and security

Phase Transformation in Monolayer Molybdenum Disulphide with and without Defects under Tension Predicted by Atomistic Simulations

In addition to its use as a solid lubricant, molybdenum disulphide (MoS2) has gained recent attention as a possible substitute for silicon as it is increasingly difficult to keep shrinking down electronic devices made of silicon, the conventional electronic material. When thinned down to atomic thickness, monolayer MoS2 possesses very unique and promising electronic and electrical properties. Unlike electronic and electrical properties, knowledge of the mechanical properties and role of structural defects on these properties of monolayer MoS2 is unexplored. For this thesis, the two main objectives are (1) to gain insight about the failure mechanism of monolayer MoS2 by modeling nanoindentation performed on suspended free standing membrane with comparison to experiment and (2) to explore the influence of structural defects on the mechanical properties of monolayer MoS2 by modelling monolayer MoS2 membranes with defects and simulating the same nanoindentation process as in part (1). It is shown that the force required for fracture of the MoS2 monolayer increases with increasing indenter diameter. This relationship and the magnitudes of the breaking forces computed in this work are consistent with experiments presented in the literature. A phase transformation, caused by an abrupt drop in the S-S intralayer Z dimension, is observed prior to failure during both defect-free and defect-containing membrane simulations. This phase transformation is also observed in uniaxial tension simulations. Analysis suggests that structural defects alter the failure mechanisms of monolayer MoS2 and thus reduce its mechanical performance. For point defects, the phase transformation initiates from accumulated vacancies away from the center of the membrane and accelerates the new phase propagation process. For grain boundary structures, it was found that their fracture strength is independent of the grain boundary energy