Wang Ruchuan

Wavelet analysis method for detection of DDoS attack on the basis of self-similarity

As the traditional methods were not suitable for the detection of small distribute denial of service (DDoS) attack and identification of busy traffic, on the basis of the influence of DDoS attack, one wavelet analysis method was proposed. Wavelet method of coefficient variance analysis was deduced and a software model for the method was designed. In addition, key issues of the choice of wavelet and calculation of Hurst were resolved. The experimental results show that the proposed method has more advantages in accurately identifying busy traffic and detection of small DDoS attack.

Topology control based on quantum genetic algorithm in sensor networks

Nowadays, two trends appear in the application of sensor networks in which both multi-service and quality of service (QoS) are supported. In terms of the goal of low energy consumption and high connectivity, the control on topology is crucial. The algorithm of topology control based on quantum genetic algorithm in sensor networks is proposed. An advantage of the quantum genetic algorithm over the conventional genetic algorithm is demonstrated in simulation experiments. The goals of high connectivity and low consumption of energy are reached.

The study of network worm propagation simulation

Network worm propagation is one of the most interesting and complex topics in the field of network security. The current study of network worm propagation is mainly carried out in the simulation environment since it is unpredictable and harmful to do the experiments in the real world. Simulation of network worm propagation needs to meet the special requirements of the large-scale individual, strong randomness, high concurrency. Compared with a variety of popular simulation software, NetLogo which developed by Northwestern University is chosen as the platform. The Simulation of classic worm propagation model, complex network and worm active/passive dissemination is designed and implemented in this paper. Moreover the evolution process can be configured, controlled and observed. The experimental results show that the simulation is better than the traditional MATLAB simulation.

An Exact Top-k Query Algorithm with Privacy Protection in Wireless Sensor Networks

Aimed at the Top-k query problems in the wireless sensor networks (WSN) where enquirers try to seek the k highest or shortest reported values of the source nodes, using privacy protection technology, we present an exact Top-k query algorithm based on filter and data distribution table (shorted for ETQFD). The algorithm does the query exactly and meanwhile uses conic section privacy function to prevent the disclosure of the real data and then to promise the security of nodes in network. In this proposal, each node in WSN uses data distribution table to reflect the distribution of its own data and keeps exact filter to just return data which is possibly to be the result of the query, so as to reduce the energy cost of network and prolong network lifetime. In addition, data of node is packaged with a privacy protection function based on conic section. The algorithms performance is examined with respect to a number of parameters using synthetic datasets. Performance analysis and simulation results illustrate that, compared to existing algorithms, ETQFD is energy-efficient and the network lifetime in our algorithm is longer. At the same time, privacy of data in this algorithm is also guaranteed.

Privacy Protection Based on Key-changed Mutual Authentication Protocol in Internet of Things

This paper concentrates in the privacy protection in Internet of things. It firstly focuses on the security issues and attack risks of Internet of things from four aspects, which are perception layer, transport layer, application layer and the integrated networking system. And it puts forward some proposals on wireless sensor network and RFID (Radio Frequency Identification) security system structure. The researches are theoretical basis in security defense of Internet of things. Furthermore, in order to reduce the security risks in Internet of things communication process, this paper puts forward key-changed mutual authentication protocol. The protocol integrates random number generator in the tag and reader, and adopts the one-way Hash function, key refresh in real time, key backup and other mechanisms. The analysis shows that this protocol is able to be well applied to low cost Internet of things system and effectively prevent the network from replay, replication, denial of service, spoofing and tag tracking attacks.

Ant colony algorithm for solving QoS routing problem

Based on the state transition rule, the local updating rule and the global updating rule of ant colony algorithm, we propose an improved ant colony algorithm of the least-cost quality of service (QoS) unicast routing. The algorithm is used for solving the routing problem with delay, delay jitter, bandwidth, and packet loss-constrained. In the simulation, about 52.33% ants find the successful QoS routing, and converge to the best. It is proved that the algorithm is efficient and effective.

A new subjective trust model in grid computing

According to character of grid computing, the subjective trust model is proposed. It discriminates the trust relationships between entities in the same domain and in different domains and handles the two different trust relationships with different modeling methods.

Research on Handover Algorithm for LEO Satellite Network

Low Earth Orbit (LEO) satellite networks are playing an important role in current global mobile communications. An optimized handover scheme can greatly improve performance in respect of end-to-end communication delay and link bandwidth utilization of LEO satellite networks. Various handover schemes in LEO satellite networks are researched in this paper. Ground-satellite link handover and recomputing routes problem is analyzed in detail. Then, a link handover algorithm for LEO satellite mobile communication network is proposed. Simulation results show that the satellite link handover algorithm proposed has less end-to-end delay, and is more stable and customizable.

Distributed GEP query optimization on grid service

In order to better solve the problem of distributed query optimization, a querying optimization algorithm on GEP (QO-GEP) is present. On the basis of QO-GEP, distributed GEP query optimization on grid service (DGEPQO-GS) is proposed which combines with grid service. Simulated experiments shows that with the increment of the number of query relation, query time which QO-GEP carries out querying decreases apparently, meanwhile, with the number of grid nodes, the average querying success rate of DGEPQO-GS increases significantly.

A secure model for mobile agent based on encrypted circuit construction

As a new technology, mobile agent (MA) shows a wide application in the field of network technology. However, security has been one of the crucial problems in its application. A new protection model based on a trusted element is presented in this paper. The trusted element, which differs from the traditional trusted hardware such as a smart card or a co-processor, offers a third party service based on an encrypted circuit construction. The procedure of constructing an encrypted circuit is introduced and the method of using the trusted service to protect the MA is also described. An application example is given to show how to use the new model at the end of the paper.