Group Key Rekeying Technique with Secure Data Encryption in MANETs

A Mobile Ad hoc Network (MANET) is a collection of autonomous nodes or mobile devices that can arrange themselves in various ways and operate without strict network administration. Ensuring security in mobile ad hoc network is a challenging issue and most of the applications in mobile ad hoc networks involve group-oriented communication. In Mobile ad-hoc network, each node treated as a terminal and also acts as an intermediate router. In this scenario, multi-hop occurs for communication in mobile ad hoc network. There may be a possibility of threats and malicious nodes in between source and destination. Providing the security in MANET is entirely different from the traditional wired network. In the present scenario, various applications of the mobile ad hoc network have been proposed and issues are solved by using the cryptographic techniques. Mostly cryptographic techniques are used to provide the security to MANETs. Cryptographic techniques will not be efficient security mechanism if the key management is weak. The purpose of key management is to provide secure procedures for handling keys in the cryptographic technique. The responsibilities of key management include key generation, key distribution, and key maintenance. Several key management schemes have been introduced for MANETs. The Group key management scheme is an efficient method for key management in MANET. In group key management scheme, rekeying is used whenever a new node joins or existing node leaves from the group. In this paper, we propose a periodic rekeying method (PRK) and analyze the performance of LKH rekeying techniques in a group key management schemes. The symmetric encryption techniques are analyzed with different parameters, such as Throughput and Energy consumption. Security and performance of rekeying protocols are analyzed through detailed study and simulation

Preferential solvation and bimolecular quenching reactions of boronic acid dye at very low quencher concentrations studied by fluorescence spectrum in toluene and butanol binary mixtures

168-177Inferable from the significance of solvent mixtures in practical chemistry, toluene (TL) and butanol (BL) mixtures are used to studyfluorescence behavior of boronic acid dye 2-methoxy-5-fluoro-phenyl boronic acid (2MEFPBA). At the inception, preferential solvation is examined in TL-BL, to understand specific and nonspecific interactions. Suppan’s dielectric enrichment model is further used to understand the nonideality and dielectric enrichment in TL-BL mixtures for preferential solvation. Bimolecular quenching reaction studies of 2MEFPBA with aniline as quencher are made in mixtures of TL–BLto know the effect of viscosity and dielectric constant variation at room temperature.  The quenching process is studied in all solvent mixtures by steady state and transient state method. Quenching is characterized by S-V plots having upward curvature. Analysis of modified S-V equations which accounts both static and dynamic quenching allows calculating bimolecular quenching rate constant. The bimolecular quenching reactions are found to be significantly larger. Further finite sink approximation model is invoked so as to check whether reactions are diffusion limited. The extents of these rate parameters demonstrate that positive deviations in the Stern-Volmer (S-V) plot are because of the presence of apparent static and dynamic quenching process

GPRKEY - A NOVEL GROUP KEY REKEYING TECHNIQUE FOR MANET

A Mobile Ad hoc Network (MANET) is a collection of autonomous nodes or mobile devices that can arrange themselves in various ways and work without strict network administration. Ensuring security in mobile ad hoc networks is a challenging issue and most of the applications in mobile ad hoc networks involve group oriented communication. Mostly cryptographic techniques are used to provide the security to MANETs. Cryptographic techniques will not be efficient security mechanism if the key management is weak. The issue of packet loss in MANET that is caused due to multi casting and backward and forward secrecy results in mobility. Hence, we investigate on this issue and propose a method to overcome this scenario. On analysing the situation we find that frequent rekeying leads to huge message overhead and hence increases energy utilization. With the existing key management techniques it causes frequent disconnections and mobility issues. Therefore, an efficient multi casting group key management will help to overcome the above problems. In this paper we propose a novel group key rekeying technique named GPRKEY (Group key with Periodic ReKEYing) deal with scalability issue of rekeying and also analyze the performance of the newly proposed key management method using key trees. In this approach we use the periodic rekeying to enhance the scalability and avoid out of sync problems. We use sub trees and combine them using the merging algorithm and periodic re-keying algorithm. The GPRKEY is evaluated through NS-2 simulation and compared with existing key management techniques OFT (One-way Function Tree) and LKH (Logical Key Hierarchy). The security and performance of rekeying protocols are analyzed through detailed study and simulation

Preferential solvation and bimolecular quenching reactions of boronic acid dye at very low quencher concentrations studied by fluorescence spectrum in toluene and butanol binary mixtures

Inferable from the significance of solvent mixtures in practical chemistry, toluene (TL) and butanol (BL) mixtures are used to studyfluorescence behavior of boronic acid dye 2-methoxy-5-fluoro-phenyl boronic acid (2MEFPBA). At the inception, preferential solvation is examined in TL-BL, to understand specific and nonspecific interactions. Suppan’s dielectric enrichment model is further used to understand the nonideality and dielectric enrichment in TL-BL mixtures for preferential solvation. Bimolecular quenching reaction studies of 2MEFPBA with aniline as quencher are made in mixtures of TL–BLto know the effect of viscosity and dielectric constant variation at room temperature. The quenching process is studied in all solvent mixtures by steady state and transient state method. Quenching is characterized by S-V plots having upward curvature. Analysis of modified S-V equations which accounts both static and dynamic quenching allows calculating bimolecular quenching rate constant. The bimolecular quenching reactions are found to be significantly larger. Further finite sink approximation model is invoked so as to check whether reactions are diffusion limited. The extents of these rate parameters demonstrate that positive deviations in the Stern-Volmer (S-V) plot are because of the presence of apparent static and dynamic quenching process

The Antidepressant like action of ethanolic extract of areca catechu on behavioral models of depression in rats

Background: The objective was to investigate the anti-depressant like activity of areca catechu nut ethanolic extract (ACEE) using behavioural tests in rats.Methods: Forced swim test (FST) and tail suspension test (TST) were used to assess the anti-depressant like effect of ACEE rats. Motor coordination was also assessing using rota-rod test in rats to see generalised CNS depression. Fluoxetine was the reference standard drug. Rats were divided into four groups with six rats in each group namely control group, fluoxetine 10 mg/kg group, ACEE 50 mg/kg group and fluoxetine 5 mg/kg plus ACEE 25 mg/kg. All treatments were administered orally.Results: The areca nut ethanolic extract (ACEE) (50mg/kg oral) exhibited anti-depressant like activity i.e. decrease the duration of immobility time (sec) in acute forced swim test (FST) and in acute tail suspension test (TST) in rats (104±1.7, 95%CI 99.65 to 108.4, p <0.01) Vs control and (136.3±1.94, 95%CI 131.3 to 141.3, p<0.01) Vs control respectively. ACEE in low dose of 25 mg potentiated the anti-depressant activity of low dose fluoxetine 5 mg/kg in both the test 102.3±2.60, CI 95.64 to 109.0 p<0.01) Vs control. The ACEE did not produce motor incoordination in rats.Conclusions: The results of present study suggest that the areca catechu nut ethanolic extract 50mg/kg possess potential anti-depression like effect without generalized CNS depression. Further studies are needed to confirm this

Effect of hydrogen bonding and solvent polarity on the fluorescence quenching and dipole moment of 2-methoxypyridin-3-yl-3-boronic acid

Two photophysical properties namely, fluorescence quenching and dipole moment (both ground state and excited state) of 2-methoxypyridin-3-yl-3-boronic acid (2MPBA) have been investigated in alcohol environment using steady state fluorescence technique at 300 K. In quenching studies, a rare but not unusual observation; negative Stern-Volmer (S-V) deviation has been noticed. It has been explained using the concept of solute’s conformational changes in the ground state due to inter-molecular and intra-molecular hydrogen bonding in alcohol environment. The spectroscopic data has been processed using Lehrer equation and thereby Stern-Volmer constant (KSV) has been evaluated. It has been found to be above 100 for most of the solvents used. The data related to dipole moment has been examined using different solvent polarity functions. Theoretical calculation of dipole moment in the ground state has been done using Gaussian software. The general solute–solvent interactions and hydrogen bond interactions have been found to be operative. An appreciable red shift of about 25 nm in the emission spectra has been identified with the rise in solvent polarity and decrease in molar mass of alcohols. It confirms the π→π* transition as well as the possibility of intra-molecular charge transfer (ICT) character in the emitting singlet state of 2MPBA

A hybrid fuzzy sliding-mode control for a three-phase shunt active power filter

This document is the Accepted Manuscript version of the following article: Mohamed Abdeldjabbar Kouadria, Tayeb Allaoui, and Mouloud Denai, ‘A hybrid fuzzy sliding-mode control for a three-phase shunt active power filter’, Energy Systems, Vol. 8 (2): 297-308, March 2016. The final publication is available at Springer via http://dx.doi.org/10.1007/s12667-016-0198-4.This paper describes the hybrid fuzzy sliding-mode control (HFSMC) for a three phase shunt active shunt filter for the power quality improvement. The Power Quality (PQ) problems in power distribution systems are not new but only recently the effects of these problems have gained public awareness. These non-linear loads are constructed by nonlinear devices in which the current is not proportional to the applied voltage. For the harmonic elimination different methods are used, but in this paper a novel fuzzy logic controller for a three-phase shunt active power filter for the power quality improvement such as reactive power and harmonic current compensation generated due to nonlinear loads. The hybrid fuzzy sliding-mode control (HFSMC) approach is proposed such that it can be applied with advantages to both fuzzy and sliding-mode controller. Simulation results are presented to demonstrate the effectiveness of the control strategy. The results are found to be quite satisfactory to mitigate harmonic distortions, reactive power compensation and power quality improvement.Peer reviewedFinal Accepted Versio