Abstract:Context-Aware recommender systems, aiming to further improve performance accuracy and user satisfaction by fully utilizing contextual information, have recently become one of the hottest topics in the domain of recommender systems. This paper presents an overview of the field of context-aware recommender systems from a process-oriented perspective, including system frameworks, key techniques, main models, evaluation, and typical applications. The prospects for future development and suggestions for possible extensions are also discussed.

Abstract:With the rapid development of affective computing and facial expression analysis, it is important to understand trusted facial expressions during human-computer interaction. This paper presents a novel approach for synergetic trust analysis of facial expression. Based on the cooperative mechanism between facial expression features and affective trust evidences, the synergy theory is applied to extend the evidences and to achieve the reasoning algorithm in a proactive environment. The resultant model from cooperative interaction and synergetic dependence evaluation is potentially capable of analyzing the trusted facial expression. Experiments have been conducted to evaluate the rationality of the approach. It is suggested that synergetic trust model can reduce the subjective impacts of overall analysis and perform at a higher credibility can allow the user to further comprehend affective computing with trust factors.

Abstract:In many areas such as science, simulation, Internet, and e-commerce, the volume of data to be analyzed grows rapidly. Parallel techniques which could be expanded cost-effectively should be invented to deal with the big data. Relational data management technique has gone through a history of nearly 40 years. Now it encounters the tough obstacle of scalability, which relational techniques can not handle large data easily. In the mean time, none relational techniques, such as MapReduce as a typical representation, emerge as a new force, and expand their application from Web search to territories that used to be occupied by relational database systems. They confront relational technique with high availability, high scalability and massive parallel processing capability. Relational technique community, after losing the big deal of Web search, begins to learn from MapReduce. MapReduce also borrows valuable ideas from relational technique community to improve performance. Relational technique and MapReduce compete with each other, and learn from each other; new data analysis platform and new data analysis eco-system are emerging. Finally the two camps of techniques will find their right places in the new eco-system of big data analysis.

Abstract:With the coming of 3G ages and the high-speed growth of Web resources, there is a trend of rapid development in mobile Internet, making resources accessesible and information obtainable conveniently by using mobile devices. However, in mobile Web search, these are very challenging tasks to geo-tag Web resources, integrated spatial data and Web data seamlessly, and provide valuable and high-relevant information to users. A framework of mobile Web search is proposed in this paper, and the key research techniques in mobile Web search are classified and surveyed according to this framework. Based on the comprehensive comparison and analysis of existing techniques, the suggestions for future research are put forward.

Abstract:BGP (border gateway protocol) is widely known for some problems in terms of poor reliability, suboptimal path use, and insufficient support for load balancing because it is a single-path routing protocol. Inter-Domain multipath routing explores the underlying network AS-level path diversity to improve the Internet’s reliability, performance, and resource utilization. Thus, inter-domain multipath routing is considered a useful and necessary method to address the problems faced by BGP. This paper surveys current proposals on inter-domain multipath routing protocols and classifies these protocols into three categories: Protocols on a single announcement and multipath forwarding, protocols on multiple announcements and multipath forwarding, and new Internet routing architecture based protocols. They are compared under some different features of path diversity, control message overhead, loop-freeness property, etc. In addition to a review of existing protocols, the challenges in designing new inter-domain multipath routing protocols that could be taken as the future research direction are pointed out.

Abstract:Botnets are one of the most serious threats to the Internet. Researchers have done plenty of research and made significant progress. However, botnets keep evolving and have become more and more sophisticated. Due to the underlying security limitation of current system and Internet architecture, and the complexity of botnet itself, how to effectively counter the global threat of botnets is still a very challenging issue. This paper first introduces the evolving of botnet’s propagation, attack, command, and control mechanisms. Then the paper summarizes recent advances of botnet defense research and categorizes into five areas: Botnet monitoring, botnet infiltration, analysis of botnet characteristics, botnet detection and botnet disruption. The limitation of current botnet defense techniques, the evolving trend of botnet, and some possible directions for future research are also discussed.

Abstract:One of the challenges the current Internet faces is the scalability of routing system. The rapid growth of routing table and the more and more frequent updates of BGP are bringing heavy pressure on the performance, complexity, energy consumption and cost of core routers. In recent years, many researchers have been seeking solutions for these issues. One of the key research directions is splitting the current IP address into separate identifiers and locators. This paper proposes a novel ID/locator split solution, which forms dual IP address spaces architecture. It overcomes the difficulty of implementation and deployment. Also, it not only mitigates the routing scalability issue, but also solves the IPv4 address exhaustion problem. Besides simple modification on DNS and installation of a gateway for each user network, the original backbone network and user networks do not need any modification.

Abstract:A variety of QoS guarantee is to be needed in the real-time transmission of video stream in wireless multimedia sensor networks. A multi-path routing algorithm ACMRA (ant colony based multipath routing algorithm) based on improved ant colony algorithm is proposed in this paper to find the paths set which includes paths according to different priorties. It also takes the importance of video data into consideration when making path choice. The improved ant colony algorithm enjoys faster finding and convergence speed by optimizing the initial distribution of artificial pheromone on network link. By introducing the multi-path mechanism throughput, the network and video transmission performance are both enhanced, while it also balances network resources and prolongs the network life cycle. Compared with the other classic routing algorithm, the experimental results illustrate that ACMRA has obvious advantages in terms of raising network, video transmission performance, and extending the network life cycle.

Abstract:The coexistence of multi-primary users and multi-secondary users in cooperative cognitive radio networks motivate the study to propose a joint spectrum allocation and cooperation set partition problem, which so far has not been addressed before. The problem is formulated as a 0-1 integer non-linear programming model. Due to its NP-hardness, the study proposes a suboptimal Centralized Genetic Algorithm (CGA) to show its convergence by modeling it as a homogeneous finite Markov chain. The study then extends CGA to a fully Distributed Genetic Algorithm (DGA) that consists of two phases. The core techniques include a minimum dominate set based cluster partition, a spectrum pre-allocation algorithm in phase 1, and an inter-cluster cooperation set negotiation and cluster fitness refinement algorithm in phase 2. A Fast-Convergent DGA (FDGA) is also devised to reduce the system configuration time. Extensive experiments by simulations demonstrate that in terms of the fitness that reflects the performance of the proposed algorithms: (1) CGA is shown to perform as well as 92% of the optimal solution by brutal search under small network sizes; (2) As the network size increases, due to the massive search space CGA has to deal, DGA and FDGA instead outperform CGA with 20% on average when achieving the same algorithm termination condition; (3) FDGA delivers similar results as DGA while reducing the configuration time significantly, which is more suitable for large-scale networks.

Abstract:This paper gives a survey of the random oracle model, which is an important tool in provable security. The random oracle model is introduced on several aspects, including its origin and development, basic properties and methodology, representative schemes, plaintext awareness, random oracle instantiation, the uninstantiable properties and related negative results, and the research of weakened random oracle models. Besides, other ideal models are compared with the random oracle model, and the construction of encryption schemes in the standard model is also referred.

Abstract:The paper reviews the current research situation of FPE (format-preserving encryption) including basic constructing methods, encryption modes and security. When describing the basic constructing methods, it introduces the basic principles of Prefix, Cycle-Walking and Generalized-Feistel and their application scopes. When explaining the encryption modes, it mainly analyzes the construction features of FPE modes or schemes, introduces the principles of three classical modes, summarizes the different types of Feistel networks and presents an overview of their applications in FPE. When talking about the security, it describes the security notions of FPE and their corresponding games, analyzing the relationship among them. In the end, it introduces the application scopes of FPE and points out that performance, integrity authentication and key problems of database encryption with FPE, such as making range query and arithmetic operation on encrypted data, are the major problems to be solved in the future. All these works will play a role in promoting research of format-preserving encryption.

Abstract:At EUROCRYPT 2009, Dinur and Shamir proposed a new type of algebraic attacks named cube attack. Grain is one of the 3 final hardware-oriented stream ciphers in the eSTREAM portfolio, which takes an 80-bit secret key and a 64-bit initial vector as input and produces its keystream after 160 rounds of initialization. Applying cube attack on Grain with 70 initialization rounds, the study finds that 15-bit secret key can be recovered and can find 4 linear equations on another 23 bits of the secret key. Moreover, 1-bit secret key can be recovered by applying cube attack on Grain with 75 initialization rounds.