Qin Zhiguang

Modeling passive worm propagation in mobile P2P networks

Passive worms pose threats to mobile P2P(peer-to-peer) networks. To predict the tendency of propagation of mobile P2P passive worms and analyze their behaviors, it is necessary to model mobile P2P passive worm propagation. In this paper, the protocols of mobile P2P networks and the features of passive worm propagation are studied. On the basis, the mathematical model of passive worm propagation is proposed in applying Epidemiology. For the purpose of examining the effect of the mobile P2P-related parameters on worm propagation, simulation experiments are carried out. The results of these experiments show that different parameters have different effect on passive worm propagation, among which the average downloading rate and the average recovery rate of fixed peers have the strongest effect on passive worm propagation among mobile peers.

Survey on Cloud Data Integrity Proof Techniques

Proof of Retrievability (POR) and Provable Data Possession (PDP) systems these days are the most active area of research for data integrity check, which is outsourced to cloud service providers. In this work we surveyed data integrity proving schemes by reviewing different schemes in the area along with their efficiency and security considerations. The objective of this survey is to offer a state-of-the-art knowledge for new researchers, who are interested in this specific area, i.e., it helps in understanding the research work carried out for the last few years.

Location management in mobile environment

In this paper, we present a comprehensive survey of the various approaches to the problem of storing, querying, and updating the location of objects in a mobile computing environment. We analyse the drawback of point location management, present the research issue for querying the mobile objects, and propose the model of moving objects based on GIS, and research the location query operators. Finally we give the implementation of some operators in our cargo delivery system.

Logical Symmetry Based K-means Algorithm with Self-adaptive Distance Metric

In this paper, we propose a modified version of the K-means clustering algorithm with distance metric. The proposed algorithm adopts a novel weighted Euclidean distance measure based on the idea of logical symmetry of points to its candidate clusters, which challenges the common assumption that the point similarity can only be determined by their physical distance to the centroids of the clusters. This kind of logical symmetry distance can be adaptively applied to many practical data clustering scenarios such as social network analysis and computer vision, in which the logical relationship of the clustering objectives is an important consideration in the design of the clustering algorithm. Several data sets are used to illustrate its effectiveness.

Collision-based chosen-message simple power clustering attack algorithm

Chosen-message pair Simple Power Analysis (SPA) attacks were proposed by Boer, Yen and Homma, and are attack methods based on searches for collisions of modular multiplication. However, searching for collisions is difficult in real environments. To circumvent this problem, we propose the Simple Power Clustering Attack (SPCA), which can automatically identify the modular multiplication collision. The insignificant effects of collision attacks were validated in an Application Specific Integrated Circuit (ASIC) environment. After treatment with SPCA, the automatic secret key recognition rate increased to 99%.

Analysis of Urban Traffic Based on Taxi GPS Data

Recently, the problem of traffic jam in major cities is getting worse. By leveraging the taxi GPS data of Shenzhen, this paper analyzes the urban traffic status and proposes rational suggestions for urban traffic management. In particular, this paper firstly presents the get-on and get-off points on GIS map based on taxi GPS data. Secondly, by using K-Means algorithm to allocate urban traffic cells, the hot areas where passenger flow is huge are pointed out. Finally, based on the taxi speed, we locate the crowded area and find the crowded period, then analyze the reasons that cause the traffic jam and propose rational suggestions for urban traffic management.

An adaptive search method based on the interest in Gnutella-like network

Search performance is the key issue for the development of the P2P network. Aiming at the flaw of existing search methods in unstructured P2P environment, an adaptive search method based on the interest is proposed. The interest overlay network is constructed according to the clustering characteristics of the peers. Due to diversity interest of every peer, the interest-domain of the peer is subdivided into several interest-themes, every peer joins in several interest groups at one time according to the similarity degree of the interest-themes. The interest relation is self-managed by the peer. Based on the similarity between the query and the interest-themes, the requesting peer adaptively guides the direction of the query. Simulation experiments show that the proposed method can effectively improve the search performance.

Identity-based threshold ring signature without pairings

Identity-based(ID-based) threshold ring signature has rapidly emerged in recent years and many schemes have been proposed until now. However, most of these ID-based threshold ring signatures are constructed from bilinear pairings, a powerful but computationally expensive primitive. Hence, ID-based threshold ring signature without pairing is of great interest in the field of cryptography. In this paper, we propose an ID-based threshold ring signature scheme without pairings. The proposed scheme is proven to be existential unforgeable against adaptive chosen message-and-identity attack under the random oracle model, assuming the hardness of factoring.

A New Technique of Anti-tampering Technology Based on AVS Video

Based on China AVS standard, this paper proposed a method of built-in video watermark technology. Authentication information was generated from I frame as the watermark, and is embedded into selected positions of later P-, B-frames. An algorithm was designed and introduced in this paper to verify the video modification status via abstracted watermark. Dependent on feature of credible encoding/decoding of AVS video, besides appropriate watermark robustness could be guaranteed, this method can minimize the watermark capacity and can reduce the impact on video, as well as detection sensitivity for video tampering of watermark algorithm could be guaranteed. The test results show that the technology proposed by this paper has almost zero effect on vision and encoding efficiency, while also can detect the position of the tampering precisely.

Performance assessment of retrieving information of moving objects with spatio-temporal index

We will present a 4 dimensional trajectory model for capturing dynamic locations of moving objects is proposed. Based upon this model, we will present a usage of query operators and implement these queries on ORDBMS and study the effect of indices on the performance of these moving object queries. Finally, the effectiveness of our approach is justified by some experiments.