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With the rise of the internet, there has been an increasing focus on user anonymity. Anonymous communication networks (ACNs) aim to protect the identity privacy of users in the network. As a typical ACN, Tor achieves user anonymity by relaying user data through a series of relay nodes. However, this results in higher latency due to the transmission of network traffic between multiple nodes. This paper proposes a port-based anonymous communication network (PBACN) to address this issue. First, we propose a path construction algorithm. This algorithm describes constructing paths by partitioning the communication path information, which can reduce the probability of being discovered by adversaries. Secondly, we design a port-based source routing addressing method. During data transmission from the source to the destination, each node can directly forward the data by resolving the address into the port of each node. This method eliminates the need for table lookups, reducing the complexity of routing. Lastly, we propose an entropy-based metric to measure the anonymity of different ACNs. In terms of experimental evaluation, we quantitatively analyze the anonymity and end-to-end delay of various ACNs. The experimental results show that our proposed method reduces end-to-end delay by approximately 25% compared to Tor. When the adversary fraction is 20%, PBACN can improve the anonymity degree by approximately 4%. [ABSTRACT FROM AUTHOR]

With the development of wireless communication and artificial intelligence technology, online parking reservation system can effectively save drivers' searching time for vacant spaces. However, in the environment with multiple candidate parking lots around the destination, how to coordinate and maximize parking space resources to reduce the travel time is still a practical issue for urban drivers. In order to solve this problem, a collaborative reservation mechanism based on dynamic vehicle path planning is proposed in this paper. By the aid of the dedicated backbone network with a clear division of work responsibilities, the information of traffic and parking lots is collected in real time, based on which the travel time prediction and empty spaces evaluation are executed separately, and then the optimal decision of path planning and parking lot selection can be made and adjusted dynamically by a step-by-step acknowledgement mechanism. The simulation results show that, based on collaborative working and overall planning, our proposed reservation mechanism can effectively raise the utilization rate of the parking lots resources and significantly reduce the travel time for drivers under different traffic environments. Compared to current mechanisms, the collaborative parking reservation mechanism reveals higher feasibility and applicability. It can assist in design and operation of urban traffic management and space resource utilization., Author(s): Yuting Xiao [1]; Zhen Cai (corresponding author) [1,2]; Jinglei Li [1]; Mangui Liang [2]; Xiaoyu Long [3] 1. Introduction With the development of urbanization and the increase of population [...]

As the most popular anonymous communication system, Tor provides anonymous protection for users by sending their messages through a series of relays. Due to the use of the bandwidth-weighted path selection algorithm, many more users choose routers with high bandwidth as relays. This will cause the utilization of high bandwidth routers to be much higher than that of low bandwidth routers, which will bring congestion risk. The Quality of Service (QoS) is difficult to guarantee for users who need delay-sensitive services such as web browsing and instant messaging. To reduce the average load of routers and improve the network throughput, we propose a circuit construction method with multiple parallel middle relays and conduct a dynamic load allocation method. The experiment demonstrates that our proposed method can provide better load balancing. Compared with other multipath anonymous communication networks, our proposed method can provide better anonymity. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The construction of data center network by applying SDN technology has become a hot research topic. The SDN architecture has innovatively separated the control plane from the data plane which makes the network more software-oriented and agile. Moreover, it provides virtual multi-tenancy, effective scheduling resources and centralized control strategies to meet the demand for cloud computing data center. However, the explosion of network information is facing severe challenges for SDN controller. The flow storage and lookup mechanisms based on TCAM device have led to the restriction of scalability, high cost and energy consumption. In view of this, a source-controlled data center network (SCDCN) model is proposed herein. The SCDCN model applies a new type of source routing address named the vector address (VA) as the packet-switching label. The VA completely defines the communication path and the data forwarding process can be finished solely relying on VA. There are four advantages in the SCDCN architecture. 1) The model adopts hierarchical multi-controllers and abstracts large-scale data center network into some small network domains that has solved the restriction for the processing ability of single controller and reduced the computational complexity. 2) Vector switches (VS) developed in the core network no longer apply TCAM for table storage and lookup that has significantly cut down the cost and complexity for switches. Meanwhile, the problem of scalability can be solved effectively. 3) The SCDCN model simplifies the establishment process for new flows and there is no need to download flow tables to VS. The amount of control signaling consumed when establishing new flows can be significantly decreased. 4) We design the VS on the NetFPGA platform. The statistical results show that the hardware resource consumption in a VS is about 27% of that in an OFS. [ABSTRACT FROM AUTHOR]

In mobile ad hoc networks (MANETs), link failures are caused frequently because of node's mobility and use of unreliable wireless channels for data transmission. Multipath routing strategy can cope with the problem of the traffic overloads while balancing the network resource consumption. In the paper, an optimized node-disjoint multipath routing (ONMR) protocol based on ad hoc on-demand vector (AODV) is proposed to establish effective multipath to enhance the network reliability and robustness. The scheme combines the characteristics of reverse AODV (R-AODV) strategy and on-demand node-disjoint multipath routing protocol to determine available node-disjoint routes with minimum routing control overhead. Meanwhile, it adds the backup routing strategy to make the process of data salvation more efficient in case of link failure. The results obtained through various simulations show the effectiveness of the proposed scheme in terms of route availability, control overhead and packet delivery ratio. [ABSTRACT FROM AUTHOR]

Outlier detection, as a type of one-class classification problem, is one of important research topics in data mining and machine learning. Its task is to identify sample points markedly deviating from the normal data. A reliable outlier detector needs to build a model which encloses the normal data tightly. In this paper, an improved one-class SVM (OC-SVM) classifier is proposed for outlier detection problems. We name this method OC-SVM with minimum within-class scatter (OC-WCSSVM), which exploits the inner-class structure of the training set via minimizing the within-class scatter of the training data. This can construct a more accurate hyperplane for outlier detection, such that the margin between the training data and the origin in a higher dimensional space is as large as possible, while at the same time the decision boundary around the normal data is as tight as possible. Experimental results on a synthetic dataset and 10 real-world datasets demonstrate that our proposed OC-WCSSVM algorithm is effective and superior to the compared algorithms. [ABSTRACT FROM PUBLISHER]

SUMMARY In this paper, we propose a novel privacy-preserving registration protocol that combines the verifier local revocation group signature with mobile IP. The protocol could achieve strong security guarantee, such as user anonymity via a robust temporary identity, local user revocation with untraceability support, and secure key establishment against home server and eavesdroppers. Various kinds of adversary attacks can be prevented by the proposed protocol, especially that deposit-case attack does not work here. Meanwhile, a concurrent mechanism and a dynamical revocation method are designed to minimize the handover authentication delay and the home registration signals. The theoretical analysis and simulation results show that the proposed scheme could provide high security level besides lightweight computational cost and efficient communication performance. For instance, compared with Yang's scheme, the proposed protocol could decrease the falling speed of handover authentication delay up to about 40% with privacy being preserved. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 FROM AUTHOR]

We propose network coding schemes for a broadcast system where the source packets exhibit a hierarchical structure, such that the successful information retrieval of a packet at a certain layer relies on the correct receptions of the packets in the previous layers. Assuming the entire transmission consists of two stages, the broadcast stage and the retransmission stage, for progressive packet information decoding, we propose novel source packet combining schemes for retransmission based on network coding. The objective is to reduce the number of retransmissions for decoding certain fraction of the source packets. The proposed schemes can be applied to scalable video broadcast systems. [ABSTRACT FROM PUBLISHER]

Transmission efficiency and robustness are two important properties of various networks and a number of optimization strategies have been proposed recently. We propose a scheme to enhance the network performance by adding a small fraction of links (or edges) to the currently existing network topology, and we present four edge addition strategies for adding edges efficiently. We aim at minimizing the maximum node betweenness of any node in the network to improve its transmission efficiency, and a number of experiments on both Barabási-Albert (BA) and Erdös-Rényi (ER) networks have confirmed the effectiveness of our four edge addition strategies. Also, we evaluate the effect of some other measure metrics such as average path length, average betweenness, robustness, and degree distribution. Our work is very valuable and helpful for service providers to optimize their network performance by adding a small fraction of edges or to make good network planning on the existing network topology incrementally. [ABSTRACT FROM AUTHOR]

Rail surface inspection plays a pivotal role in large-scale railway construction and development. However, accurately identifying possible defects involving a large variety of visual appearances and their dynamic illuminations remains challenging. In this paper, we fully explore and use the essential attributes of our defect structure data and the inherent temporal and spatial characteristics of the track to establish a general theoretical framework for practical applications. As such, our framework can overcome the bottleneck associated with machine vision inspection technology in complex rail environments. In particular, we consider a differential regular term for background rather than a traditional low-rank constraint to ensure that the model can tolerate dynamic background changes without losing sensitivity when detecting defects. To better capture the compactness and completeness of a defect, we introduce a tree-shaped hierarchical structure of sparse induction norms to encode the spatial structure of the defect area. The proposed model is evaluated with respect to two newly released Type-I/II rail surfaces discrete defects (RSDD) data sets and a practical rail line. Qualitative and quantitative evaluations show that the decomposition model can handle the dynamics of the track surface well and that the model can be used for structural detection of the defect area. [ABSTRACT FROM AUTHOR]

The urban intersection signal decision-making in traditional control methods are mostly based on the vehicle information within an intersection area. The far vehicles that have not reached the intersection area are not taken into account, which results in incomplete information and even incorrectness in decision-making. This paper presents an intersection signal control mechanism assisted by far vehicle information. Using the aid of real-time information collection for far vehicles through vehicular ad hoc networks (VANETs), we can consider them together and calculate the accumulative waiting time for each intersection traffic flow at a future moment to make the optimal signal decision. Simulation results show that, under three different traffic flow environments—same even traffic flows, same uneven traffic flows, and different traffic flows—the two proposed implementation schemes based on the mechanism (fixed phase and period timing improvement scheme, and dynamic phase and period control scheme) show good performances, in which the average waiting time and the ratio of long-waiting vehicles are both less than the results of the traditional signal timing scheme. Especially, in the second scheme, the waiting time was reduced by an average of 38.6% and the ratio of long-waiting vehicles was reduced by an average of 7.67%. [ABSTRACT FROM AUTHOR]