Datacenter networks (DCNs) play a key role in providing cloud services. The energy consumption and cost of a DCN are growing sharply with the extensions of network bandwidth and network size. The energy consumption, complexity and cost of a DCN depend on some design factors such as the topology structure, addressing scheme and routing mechanism. A novel addressing and routing architecture for cloud-service DCNs with regular topologies is proposed in this paper. First of all, we propose a port-based source-routing addressing (PSRA) scheme, which makes the table-lookup operation unnecessary and decreases the switch complexity. Next, leveraging the characteristics of PSRA and the regularity of DCN topologies, an extremely simple routing mechanism is designed, without switch involvement, control message interaction and topology information storage. Lastly, a high-efficiency fault-tolerance mechanism is proposed for the addressing and routing architecture. The analysis, implementation and simulation results indicate that the proposed architecture not only decreases the energy consumption and thus the cost of a DCN, but also enhances the routing performance and solves the fault-tolerance problem in a very efficient way.

Object instance search is a challenging task with a wide range of applications, but the fast search with high accuracy has not been well solved yet. In this paper, we investigate the object instance search from a new perspective in terms of joint precision and computational cost optimization, and propose a novel index structure i.e., Multi-Block N-ary Trie (MBNT) to accelerate the exact r-neighbor search in the Hamming space. Comprehensive studies are first carried out to reveal the performance of exact and approximate nearest neighbor (NN) algorithms for object instance search. An interesting finding that the exact search is more promising for very compact binary codes (e.g., 64-bit and 128-bit) is analyzed. Along this vein, we introduce a Trie structure, i.e., MBNT, which is specifically designed for improving the exact NN search performance in the context of large-scale object instance search. To index the binary codes, a subset of continuous bits of a binary string, denoted as a block, is regarded as an atomic indexing element. As such, the problem of lookup misses can be addressed. Theoretical analyses are also provided to show that our MBNT scheme can incur less computational cost than other hash table-based methods. Extensive experimental results on the 100M dataset have demonstrated that our method achieves faster search speed while maintaining the promising search precision towards large-scale object instance search.

ABSTRACT Intrusion detection has become an indispensable technique to ensure the security and reliability of information systems. Support vector machine (SVM) and its many improved algorithms have been successfully applied to intrusion detection systems in recent years. However, the training process of SVM ignores an important prior knowledge, the within‐class structure in the training set. In this paper, we propose an improved classification algorithm, which combines minimum within‐class scatter in Fisher discriminant analysis with traditional SVM. The central idea is to find an optimal separating hyperplane such that the margin is maximized, whereas the within‐class scatter is kept as small as possible. This new algorithm is called SVM with minimum within‐class scatter (WCS‐SVM). A set of experiments is conducted on ten benchmarking datasets and KDDCUP'99 experimental data of MIT Lincoln Laboratory to test the generalization performance of the WCS‐SVM algorithm. Experimental results show that the WCS‐SVM algorithm has better discriminatory power than traditional SVM and kernel Fisher discriminant analysis and it has higher true detection rate and lower false positive rate for intrusion detection systems. Copyright © 2012 John Wiley & Sons, Ltd.

ABSTRACT This paper presents a secure and efficient hierarchical identity‐based access authentication protocol for mobile network. First, a new mobile scheme is constructed to improve the registration performance by the port‐based vector switching; especially when there are multihops and bandwidth between the user and home network, the registration delay is greatly reduced. Second, an access authentication protocol is proposed by combining the designed mobile proposal with hierarchical identity‐based signature. It has the characteristics of identity based, local verification, concurrency and hierarchy. The whole authenticating process is divided into two phrases to precompute some time‐consuming parameters, which are important to decrease the effects of the signing/verifying. Besides, a new access router selection algorithm is given for the mobile user to choose optimal access point in this paper. The theoretical analysis and simulating results show that the proposed authentication protocol outperforms the previous ones in terms of the handover delay integrating the authentication with its security enhanced. For example, the falling speed of the new protocol's total latency is reduced about 50% and 83%, respectively, compared with the existing identity‐based‐signature‐based and Rivest–Shamir–Adleman‐based schemes. Copyright © 2012 John Wiley & Sons, Ltd.

A novel label switching architecture for all-optical label switching (AOLS) networks is firstly proposed and experimentally demonstrated. Proposed scheme adopts successful factors of existing architecture such as GMPLS, and to construct a high performance, scalable and manageable IPbased AOLS network. Similar to GMPLS, a particular label based on source routing information is attached to IP packets/burst for fast interconnection purpose rather than an option as source-routing in conventional IP framework, thus the scheme requires neither table lookup nor header replacing in the intermediate node, labeled packets will be quickly forwarded through self-routing, and the only operation in switching nodes is to strip off its part of the label which represents the output port, which eliminates the O/E/O conversion as much as possible. The benefits include simple switching process with low packet delay, higher security, and better scalability on next generation optical Internet.

The forwarding address plays an important role in constructing a communication network. In this paper, a new forwarding address suitable for next generation networks named the vector address (VA) is proposed which is different from the forwarding address coding methods of current networks. The characteristics of the VA are analyzed. Complex network theory and a theoretical analysis method are introduced to study the average address length of the VA when used to construct a global network. Simulation experiments in a practical network topology model are carried out to validate the results. The results show that not only can the VA construct a simpler, more secure, and more scalable network, but it also can accommodate many more users than an Internet Protocol (IP) network with the same address length.

With the promotion of people's demand on information security, access authentication gets more and more attention nowadays. However, most of the traditional access authentication schemes, such as 802.1X, Web authentication, etc., have a great deal of limitations and disadvantages in security and mobility. They can't meet increasing challenges especially from wireless authentication. In this paper, a new method of authentication in network is proposed. Based on RSA and Identifier Tree, it is a kind of distributed and Hierarchical design which makes authentication safer and more manageable. Besides, by employing our proposed method, the mobile authentication becomes more simple and scalable due to identifier-based characteristics. The mechanism is first analyzed and researched. Then its feasibility, security and efficiency are demonstrated. The simulation based JAVA is done for validation finally. The evaluation studies reported in this paper, reveals important issues about further research on hierarchical access authentication in network.

This paper proposes a new approach for detecting tone errors in continuous Mandarin speech. In the training phase, tone variations are modeled with context-depended MSD-HMM which considers six contextual factors instead of two in traditional triphone HMM. In the evaluation phase, the goodness of tone pronunciation is measured by Kullback-Leibler divergence (KLD) between the expected tone model and the most representative tone model. When the KLD between the two models is larger than a threshold, the tone is detected as a pronunciation error. In the ROC curve, we get the equal error rate at 2.6%.