Biblio

In this paper, a new intrusion detection mechanism is proposed based on Trust and Packet Loss Rate at Sensor Node in WSNs. To find the true malicious nodes, the proposed mechanism performs a deep analysis on the packet loss. Two independent metrics such as buffer capacity metric and residual energy metric are considered for packet loss rate evaluation. Further, the trust evaluation also considers the basic communication interactions between sensor nodes. Based on these three metrics, a new composite metric called Packet Forwarding Probability (PFP) is derived through which the malicious nodes are identified. Simulation experiments are conducted over the proposed mechanism and the performance is evaluated through False Positive Rate (FPR) and Malicious Detection Rate (MDR). The results declare that the proposed mechanism achieves a better performance compared to the conventional approaches.

A self-governing system consisting of mobile nodes that exchange information within a cellular area and is known as a mobile ad hoc network (MANET). Due to its dynamic nature, it is vulnerable to attacks and there is no fixed infrastructure. To transfer a data packet Ad-hoc On-Demand Distance Vector (AODV) is used and it's another form of a reactive protocol. The black-hole attack is a major attack that drastically decreases the packet delivery ratio during a data transaction in a routing environment. In this attack, the attacker's node acts as the shortest path to the target node itself. If the attacker node receives the data packet from the source node, all obtained data packets are excluded from a routing network. A trust-based routing scheme is suggested to ensure secure routing. This routing scheme is divided into two stages, i.e., the Data retrieval (DR), to identify and preserve each node data transfer mechanism in a routing environment and route development stage, to predict a safe path to transmit a data packet to the target node.

The group key maintenance in MANET is especially risky, because repeated node movement, link breakdown and lower capacity resources. The member movement needs key refreshment to maintain privacy among members. To survive with these characteristics variety of clustering concepts used to subdivide the network. To establish considerably stable and trustable environment fuzzy based trust clustering taken into consideration with Group key management. The nodes with highest trust and energy elected as Cluster Head and it forms cluster in its range. The proposed work analyze secure multicast transmission by implementing Polynomial-based key management in Fuzzy Trust based clustered networks (FTBCA) for secure multicast transmission that protect against both internal and external attackers and measure the performance by injecting attack models.

Performance of routing is severely degraded when misbehaving nodes drop packets instead of properly forwarding them. In this paper, we propose a Game-Theoretic Adaptive Multipath Routing (GTAMR) protocol to detect and punish selfish or malicious nodes which try to drop information packets in routing phase and defend against collaborative attacks in which nodes try to disrupt communication or save their power. Our proposed algorithm outranks previous schemes because it is resilient against attacks in which more than one node coordinate their misbehavior and can be used in networks which wireless nodes use directional antennas. We then propose a game theoretic strategy, ERTFT, for nodes to promote cooperation. In comparison with other proposed TFT-like strategies, ours is resilient to systematic errors in detection of selfish nodes and does not lead to unending death spirals.

Dual Energy CT (DECT) has recently gained significant research interest owing to its ability to discriminate materials, and hence is widely applied in the field of nuclear safety and security inspection. With the current technological developments, DECT can be typically realized by using two sets of detectors, one for detecting lower energy X-rays and another for detecting higher energy X-rays. This makes the imaging system expensive, limiting its practical implementation. In 2009, our group performed a preliminary study on a new low-cost system design, using only a complete data set for lower energy level and a sparse data set for the higher energy level. This could significantly reduce the cost of the system, as it contained much smaller number of detector elements. Reconstruction method is the key point of this system. In the present study, we further validated this system and proposed a robust method, involving three main steps: (1) estimation of the missing data iteratively with TV constraints; (2) use the reconstruction from the complete lower energy CT data set to form an initial estimation of the projection data for higher energy level; (3) use ordered views to accelerate the computation. Numerical simulations with different number of detector elements have also been examined. The results obtained in this study demonstrate that 1 + 14% CT data is sufficient enough to provide a rather good reconstruction of both the effective atomic number and electron density distributions of the scanned object, instead of 2 sets CT data.