No abstract

Security problem is one of the most popular research fields in wireless sensor networks for both the application requirement and the resource-constrained essence. An effective and lightweight Authentication and Key Management Scheme (AKMS) is proposed in this paper to solve the problem of malicious nodes occurring in the process of networking and to offer a high level of security with low cost. For the condition that the mobile sensor nodes need to be authenticated, the keys in AKMS will be dynamically generated and adopted for security protection. Even when the keys are being compromised or captured, the attackers can neither use the previous keys nor misuse the authenticated nodes to cheat. Simulation results show that the proposed scheme provides more efficient security with less energy consumption for wireless sensor networks especially with mobile sensors.

For the serious impacts of network failure caused by the unbalanced energy consumption of sensor nodes, hardware failure, and attacker intrusion on data transmission, a low-energy-consumption distributed fault detection mechanism in a wireless sensor network (LEFD) is proposed in this paper. The time correlation information of nodes is used to detect fault nodes in LEFD firstly, and then the spatial correlation information is adopted to detect the remaining fault nodes, so as to check the states of nodes comprehensively and improve the efficiency of data transmission. In addition, the nodes do not need to exchange information with their neighbor nodes in the detection process since LEFD uses the data sensed by the node itself to detect some types of faults, thus reducing the energy consumption of nodes effectively. Performance analysis and simulation results show that the proposed detection mechanism can improve the transmission performance and reduce the energy consumption of the network effectively.

Vision-based indoor positioning technology is a practical and effective method to solve the problem of indoor positioning and navigation. Compared to Bluetooth-based and WiFi-based positioning methods, vision-based positioning method can provide reliable and low-cost services using a camera without extra pre-deployed hardware. To improve the robustness and accuracy of traditional visual positioning algorithm, this paper proposes a pixel threshold based eight-point method and an improved epipolar constraint algorithm. The traditional eight-point method only uses Euclidean distance as a selection indicator for feature points. The pixel coordinates of some feature points are distorted when the positioning scene changes, which may cause mismatch. The proposed method introduces the pixel threshold constraint to improve the quality of output feature points. Further, the epipolar constraint algorithm is modified by adding a new cost function to improve the accuracy of fundamental matrix calculation, thereby improving the positioning precision. Performance simulation analysis shows that the proposed algorithm can effectively improve indoor positioning precision. INDEX TERMS Pixel drift, pixel threshold, fundamental matrix calculation, epipolar constraint.

For the severe impact of limited energy and network attacks caused by open transmission channels on data transmission, this paper presents a low-power and secure multihop routing mechanism based on the Markov state transition theory. The random selection of transmission paths enables the network to resist typical attacks such as interference and interception, thus ensuring the security of data transmission. Meanwhile, the proposed algorithm can reduce the overall energy consumption of the network and balance the load according to the residual energy of each path. Simulation results prove that the routing mechanism proposed in this paper can improve the energy efficiency and the security of the wireless ad hoc network.