Wireless Body Sensor Network (WBAN) is a set of wearable and implantable devices capable of measuring physiological parameters and monitoring patient with chronic disease where early diagnosis is highly demanded. Several models introduced the general characterization of WBAN devices path loss considering possible shadowing due to obstruction of the signal (by the human body or any other obstacles) as well as the different postures of the human body. This paper aims at reporting an overview of WBSNs technologies, particular applications, system architecture and channel modeling. Emphasis is given to the IEEE 802.15.6 standard which enables the development of WBAN for medical and non-medical applications. The standard's performance within a time based variation and log-distance path loss is presented based on various simulations.

In this modern era of digital communication even a trivial task needs to be performed over internet which is not secure. Many cryptographic algorithms existed to provide security which facilitates secure communication through internet. As these algorithms need a secret session key, it is required to interchange this key in a secure way. In two-party communication, two clients initially share a low random (entropy) password through a secure channel to establish a secret session key. But this paradigm necessitates high maintenance of passwords, since each communicating pair requires separate passwords to establish a secure session key. In three-party communication network, each communication party shares a password with the trusted third-party (server) to exchange a secret session key. The beauty of this setting is that, even a server does not know the session key. The Password Authenticated Encrypted Key Exchange (PA-EKE) protocols have attracted a lot of curiosity to authors to propose various two-party and three-party PA-EKE protocols. Security flaws in various protocols proposed by Chang-Chang, Yoon-Yoo, PSRJ and Raj et al. inspired to design a robust, computationally efficient and highly secure protocol. This paper is an attempt to propose a secure and novel Password Authenticated 3P-EKE protocol using XOR operations and analogous (parallel) message transmission. The proposed protocol is easy to design and more secured against all types of attacks like password guessing, replay, pre-play, server spoofing etc. which made this protocol special.

In literature, there are many different forms of group authentication in conference key establishment protocols. The agents participating in a group need to authenticate each other in order to become assure that every agents that has access to the group key is an eligible member. In this paper, we informally classify different group authentication schemes, based on how the agents authenticate each other and provide examples of each class. We then improve one of the well-known key establishment protocol to an authenticated version according so that it meets one of our notions of group authentication.

In this paper, we have evaluated the performance of flooding and probabilistic flooding broadcast methods in a VANET using real city map. A comparative analysis between the performance of these methods with varying traffic density and nodes speed has been conducted. Here, we have considered real city maps extracted from US census TIGER database. Node movements are generated using Intelligent Driving Model for lane Changing (IDM_LC) through VanetMobiSim mobility generator. A different probability for message dissemination is considered for the probabilistic broadcast method to investigate an appropriate probability value that may give best results. Different node densities, Sparse, Intermediate and Dense are considered. The results obtained show that in dense traffic scenario probabilistic flooding method achieves maximum packet delivery ratio for a specific value of p (i.e. 0.1). In sparsely populated network, the PDR is low as compared to other traffic conditions. In a sparse traffic density both the method perform better at high node mobility. But in intermediate and dense traffic scenario performance of both the methods is better in low node mobility.

Cloud computing is called globalization for computer and internet. Either directly or indirectly we are using cloud technology almost every day. Today cloud computing is getting popular in every developed country, but it's not over all officially adopted in most of the 3rd world developing country like Bangladesh. This paper will show some categorize survey of continuous progress, advantages, disadvantages, dependencies, maturity of cloud computing from 2012 to till now. Also we will show recent ranking of cloud adoption in different country. Also our main target will review major barriers to adopt cloud. Finally we will propose some initial steps to adopt cloud technology in our country by studying previous trade-off factors of survey report.

Internet plays a vital role in communication. Determination of internet capability is done by Routing protocol. After a network fails, routing protocols have very slow convergence rate, which is a grave problem and needs to be tackled. Multiple Routing Configuration (MRC) is a technique which helps IP networks to recover very quickly from link and node failures. In MRC, packet forwarding persists on an optional link as soon as a failure is detected and additional information is always contained in the routers. This paper discusses the effect of packet size on throughput, packet delivery ratio, packet loss and delay for various routing protocols like OSPF, OSPF with 1 and 2 link breakage and MRC.

One of the important issues related to MANETs is the security. Grayhole attack is one of the most prominent attacks on the network layer of MANET which tends to degrade the network performance by performing selective packet dropping. In this paper, we propose a security mechanism that tends to mitigate the Grayhole attack during the route discovery time as well as during data transmission time. We modify AODV protocol such that it can avoid Grayhole attacker node from participating in the data transmission route, and if the attacker node somehow enters the route, it can be detected through the promiscuous mode monitoring.