We are well aware about problems persists in typically text-based passwords. Users generally choose memorable passwords, that are easy for attackers to guess, but the strong system generated passwords are difficult to remember. So a password authentication system should emphasis on maintaining high password strength on one hand and memorability on other. In this paper we’ll discuss about Persuasive Cued Click-Points i.e. persuasive click based graphical password system, which provide password strong password along with memorability. In this paper we’ll present perspective view of graphical passwords for authentication. In this work we will also conduct comprehensive analysis of the existing image based password techniques. We’ll discuss strengths and limitations of each method.

Keywords: authentication, guessing attacks, graphical passwords, PCCP, CCP.

A proposed Multi-cloud computing framework allows dynamic resource sharing among cloud-based system, addressing trust, policy, and privacy issues without pre-established collaboration agreement. Multi-cloud typically consists of service providers (or admin), infrastructure providers, and service users (or clients). Service provider(or admin) delivers applications as services to the service users (or clients) and infrastructure providers provide media of communication to service providers and clients. In our project cloud service provider(CSP) gets the applications requested by the user form the cloud and Proxy service provider(PSP) provides the communication path between different clouds. Cloud computing characteristics include a ubiquitous (network-based) access channel, resource pooling, automatic and elastic provisioning and release of computing capabilities and metering of resource usage (typically on a pay-per-use basis).
Index Terms – cloud service provider, proxy service provider, file upload, file download, hash security keys

Intrusion Detection and Prevention Systems (IDPS) are used: to identify possible attacks, collecting information about them and the trying to stop their occurrence and at last reporting them to the system administrator. These systems are used by some organizations to detect the weaknesses in their security policies, documenting existing attacks and threats and preventing an individual from violating security policies. Because of their advantages these systems became an important part of the security infrastructure in nearly every organization. In a Cloud computing environment, attackers can determine the vulnerabilities in the cloud systems and compromise the virtual machines to set out large scale Distributed Denial-of-Service (DDOS) attack. To avert these virtual machines from concession, we propose a multi-phase solution NICE (Network Intrusion Detection and Countermeasure selection in Virtual Network Systems).

Mobile ad-hoc network is a collection of node which is self-configuring, decentralized, frameworkless mobile network. Due to open nature of the network it is easily vulnerable to various attacks. The major security threat on MANET is a DDoS attack. DDoS attack has the ability to create huge amount of unwanted traffic. Due to this the authorized user cannot utilized the resources properly. It is very hard to detect and control the DDoS attack due to large scale and complex network environments. The packet marking technique is not feasible because to it consume more memory and poor measurability. In this paper, we use local flow monitoring for detecting DDoS attack based on entropy variation.
Index Term- MANET, DDoS, Flow Monitoring

New wireless sensor network applications (e.g., military surveillance) require higher reliability than a simple best effort service could provide. Classical reliable transport protocols like Transmission Control Protocol (TCP) are not well suited for wireless sensor networks due to both the characteristics of the network nodes (low computing power, strong energy constraints) and those of the main applications running on those nodes (low data rates). Recent researches present new transport protocols for wireless sensor networks providing various type of reliability and using new mechanisms for loss detection and recovery, and congestion control. This paper presents a survey on reliable transport protocol for WSNs.

Keywords: Wireless Sensor Networks, Transport Protocol, Reliability, Congestion Control, Energy Efficiency

Security is an indispensable concern in Wireless Sensor Network (WSN) due to the presence of potential adversaries. For secure communication in infrastructure less sensor nodes various key predistribution have been proposed. In this paper we have evaluated various existing deterministic, probabilistic and hybrid type of key pre-distribution and dynamic key generation algorithms for distributing pair-wise, group-wise and network-wise keys and we have propose a key pre distribution scheme using deterministic approach based on combinatorial design and traversal design which will improve the resiliency and achieve sufficient level of security in the network. This design can be used where large number of nodes is to be deployed in the WSN.

Keywords: Sensor nodes (SN), combinatorial design, Key pre-distribution scheme (KPS), Resiliency, Symmetric balanced incomplete block design (SBIBD), Traversal design

The design methodology, analysis and characterization of a radio frequency micro electromechanical systems (RF MEMS) based on reconfigurable antenna operating in wireless communications are been presented in this paper. Now- a -days multi- band antennas have became very important in the applications of wireless local- area networks (WLANS)  which are been employed for different multiple standards. Some of these standards are like IEEE 802.11b/g having a band of 2.4-2.484 GHZ; IEEE 802.11a has 5.15-5.35 GHZ and an additional band of 5.725- 5.825 GHZ and HiperLANS having a band from 5.47-5.725 GHZ. Apart from the Local area networks we have some of the other frequency ranges in the mobile networks which use RF MEMS. Some of them are like Airtel requires GSM- 900/1800 (EDGE) and 2100 MHZ HSPA, and Reliance of CDMAOne, GSM - 900/1800 and HSPA- 2100 MHZ. In this paper we can see the designing of a compact antenna that can support 2.4/5 GHZ bands. Design and characterization of the RF MEMS on reconfigurable antenna in the wireless Local area network is done and in addition mobile networks frequency can be added.