Group Key Management Techniques

The most widely used technique in a network is Group communication. This helps in the reduction of the bandwidth usage. The major concern in group communication is its security of messages. Group key provides security of messages and hence proper group key management is very important in a group communication. There are various classifications of group key management techniques. A survey of these key management techniques is done in this paper

Effect of spatial sampling on pattern noise in insect-based motion detection

Insects perform highly complicated navigational tasks even though their visual system is relatively simple. The main idea of work in this area is to study the visual system of insects and to incorporate algorithms used by them in electronic circuits to produce low power, computationally simple, highly efficient, robust devices capable of accurate motion detection and velocity estimation. The Reichardt correlator model is one of the earliest and the most prominent biologically inspired models of motion detection developed by Hassentein and Reichardt in 1956. In an attempt to get accurate estimates of yaw velocity using an elaborated Reichardt correlator, we have investigated the effect of pattern noise (deviation of the correlator output resulting from the structure of the visual scene) on the correlator response. We have tested different sampling methods here and it is found that a circular sampled array of elementary motion detectors (EMDs) reduces pattern noise effectively compared to an array of rectangular or randomly selected EMDs for measuring rotational motion

Effective Disaster Management by Efficient Usage of Resources

Disaster Management can be merely defined as the organization and management of resources and responsibilities for dealing with all humanitarian aspects of crises, in specific preparedness, rejoinder and recapture in order to diminish the influence of disasters. But the affects of the disaster increases only when the information about the disaster is unknown and when the resources for the disaster management is not correctly used. Now there are several methods for forecast the disaster, But there are no any effective methods for handling the resources needed for both managing the disaster and also for rehabilitation purpose. Thus this paper proposes an application used for managing the disaster and handling the rehabilitation process. This application which deals with almost all the resources those are required for the management of disaster. This proposed application which is based on java programming language. This project also has a great scope of enhancement in future

Modelling of bio-inspired vision system for velocity estimation.

Although motion processing in insects has been extensively studied for over almost 40 years, velocity detection in insects and how the insect brain computes the velocity of a moving feature, independent of its size or contrast, is a major enigma that remains unsolved. This study examines the accuracy of velocity estimation using two biologi-cally inspired models of motion detection, (i) the Horridge template model and (ii) the Reichardt correlator model. Various extensions and enhancements of these models are implemented with the goal of achieving robust velocity measurements. The template model is one of the prominant models of motion detection, which was proposed by Horridge in 1990. This Thesis further extends this model with the aim of improving accuracy in velocity detection using chrominance as well as luminance channels with various error checking mechanisms using different stimuli. Then the template model response is compared with Dror's elaborated Reichardt model and electro-physiological experimental results obtained from the fly visual system using similar stimuli in each case. A modified Reichardt model is shown to give a more similar response to that of fly neurons. In order to improve velocity performance of the Reichardt model, it is necessary to reduce contrast dependance of the correlator response as well as to make it independent of the structure of the visual stimuli. With this aim, the Reichardt model is then further elaborated to include contrast adaptation by a feedback adaptive mechanism and a clear reduction in contrast dependency is demonstrated. The deviation of the correlator response depending on the stimulus is termed as pattern noise. To reduce this pattern noise, the Reichardt correlator model is further extended to implement compressive non-linearity or saturation. It is seen that saturation has a profound effect on the shape of the pattern noise. Further studies on pattern noise is then performed in this Thesis using different stimuli at different speeds and contrasts. Work carried out in this Thesis on the affect of various receptive field shapes on the pattern noise reveals circular sampled arrays reduce pattern noise and hence, based on this result, a small 16 pixel yaw sensor using our elaborated model is built that shows promising performance with various potential applications.Thesis (Ph.D.) -- University of Adelaide, School of Electrical and Electronic Engineering, 200

Protection from Application Layer DDoS Attacks for Popular Websites

ENGLISH ABSTRACT: This article presents and discusses two cases from the Qurʾān and the early Islamic post-qurʾānic period that may be relevant to the overall topic of this special issue, “Salvation through impurity (anomic practice)”: 1) The so-called ‘drunken’ or ‘intoxicated’ Islamic mystics, here represented by the Persian ṣūfī al-Ḥusayn b. Manṣūr al-Ḥallāj (d. 922); and 2) the state of iḥrām, which is the holy state that a Muslim enters in connection with the minor and major Islamic pilgrimage. Based on the two cases, which I have termed an obvious and an unobvious example of the positive (post)Axial relation between salvation and anomic practice, I propose the analytical distinction between a ‘temporary’ and ‘permanent’ ‘fetishism with impurity’. Whereas the drunken ṣūfīs seem to pursue a more permanent anomic – and perhaps impure – mode of being, the qurʾānic descriptions of the state of iḥrām indicate a temporary and controlled exit from and entry back into the normal system. I argue that such a negotiation, and ultimately archaic solution, could be a result of the Qurʾān being a complex, conflictual, and tension-filled post-Axial compromise from its very beginning. DANSK RESUMÉ: I denne artikel præsenterer og diskuterer jeg to cases fra henholdsvis Koranen og den tidlige islamiske post-koraniske periode som kan være relevante for dette temanummers overordnede tema): 1) De såkaldte ‘fulde’ eller ‘berusede’ islamiske mystikere repræsenteret her af den persiske ṣūfī al-Ḥusayn b. Manṣūr al-Ḥallāj (d. 922); og 2) iḥrām-tilstanden, som er den hellige tilstand man som muslim indtræder i i forbindelse med den lille og store islamiske pilgrimsfærd. Med udgangspunkt i de to cases, som jeg har kaldt et oplagt og et uoplagt eksempel på en positiv (post-)aksial forbindelse mellem frelse og anomisk prasisk, foreslår jeg den analytiske skelnen mellem en ‘temporær’ og en ‘permanent urenhedsfetichisme’. Hvor de fulde ṣūfīer synes at søge en mere permanent anomisk – og måske uren – situation, er de koraniske beskrivelser af iḥrām-tilstanden en temporær og kontrolleret exit fra og entry tilbage til det normale system. Jeg argumenterer for, at en sådan forhandling, og i sidste ende arkaisk løsning, kan skyldes at Koranen allerede fra sin begyndelse var et komplekst, konfliktuelt og spændingsfyldt post-aksialt kompromis

A Secure and Efficient Lightweight Symmetric Encryption Scheme for Transfer of Text Files between Embedded IoT Devices

Recent advancements in wireless technology have created an exponential rise in the number of connected devices leading to the internet of things (IoT) revolution. Large amounts of data are captured, processed and transmitted through the network by these embedded devices. Security of the transmitted data is a major area of concern in IoT networks. Numerous encryption algorithms have been proposed in these years to ensure security of transmitted data through the IoT network. Tiny encryption algorithm (TEA) is the most attractive among all, with its lower memory utilization and ease of implementation on both hardware and software scales. But one of the major issues of TEA and its numerous developed versions is the usage of the same key through all rounds of encryption, which yields a reduced security evident from the avalanche effect of the algorithm. Also, the encryption and decryption time for text is high, leading to lower efficiency in IoT networks with embedded devices. This paper proposes a novel tiny symmetric encryption algorithm (NTSA) which provides enhanced security for the transfer of text files through the IoT network by introducing additional key confusions dynamically for each round of encryption. Experiments are carried out to analyze the avalanche effect, encryption and decryption time of NTSA in an IoT network including embedded devices. The results show that the proposed NTSA algorithm is much more secure and efficient compared to state-of-the-art existing encryption algorithms