Hanwen Zhang

Chinese Academy of Sciences, Peping, Beijing, China

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Publications (8)1.98 Total impact

  • Fei Wang · yongjun xu · Hanwen Zhang · Yujun Zhang · Liehuang Zhu

    No preview · Article · Jan 2015 · IEEE Transactions on Vehicular Technology
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    Miao Wang · GuiLing Wang · Jie Tian · Hanwen Zhang · YuJun Zhang
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    ABSTRACT: With the rapid growth of cloud computing, the importance of a reputation system for cloud computing services has attracted a lot of attention. Building an objective and reliable reputation scheme has been crucial to promote the development of cloud computing. To address the challenges of reputation evaluation in cloud computing, including the diverse nature of cloud services and intricacy of malicious ratings, an Accurate and Multi-faceted Reputation scheme for cloud computing (AMRep) is proposed. As the reputation systems of cloud computing are exposed to new vulnerabilities, AMRep introduces a couple of malicious rating detection approaches to improve the accuracy of reputation calculation. Additionally, we establish a multi-faceted reputation evaluation method, which can help user assess and choose cloud services from different angles. Experiments reveal that our AMRep scheme can effectively defend against malicious ratings, and accurately calculate the reputation values of cloud services.
    Full-text · Article · Dec 2014 · Procedia Computer Science
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    Yujun Zhang · Hanwen Zhang
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    ABSTRACT: The home agent can be a single point of failure in mobile IPv6 networks. This paper proposes a home agent fault-tolerant method for mobile IPv6 networks. All home agents are formed into the ring detection & backup chain in which every home agent backups its bindings on the next adjacent home agent and is monitored by the adjacent home agents. Every home agent is not only an active home agent, but also a standby one. Simulation results show that our method outperforms the current solution. Index Terms — mobile IPv6, home agent, fault-tolerant I. INTRODUCTION In mobile IPv6 networks (1), while a mobile node (MN) moves away from home, its home agent (HA) must keep track of the mode node's location and relay the packets destined to the mobile node. If a home agent fails, the mobile nodes managed by the home agent will be no longer reachable. Home agent reliability is one of the primary goals of MEXT (mobility extension for IPv6) working group of the IETF (Internet engineering task force). Mobile IPv6 protocol specifies that multiple home agents can reside in the home link, but not explain how these home agents operate. This paper proposes a new home agent fault-tolerant method for mobile IPv6 networks and gives the results of performance evaluation.
    Preview · Conference Paper · Jun 2011
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    Dizhi Zhou · Hanwen Zhang · Zhijun Xu · Yujun Zhang
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    ABSTRACT: Recently, the IETF MIPSHOP working group proposes Fast PMIPv6 (FPMIPv6) and Transient Binding PMIPv6 (TPMIPv6) to reduce the handover latency and packets loss of PMIPv6. The research and standardization of FPMIPv6 and TPMIPv6 are just in the initial stage. The system performance analysis of them is benefit to the protocol design and deployment. In this paper, through the theoretical analysis and system simulation, we evaluate the handover latency of PMIPv6, FPMIPv6 and TPMIPv6 in vertical handover environment. Furthermore, in order to reflect handover performance more comprehensively, in system simulation, we also evaluate the UDP packets loss rate and the TCP throughput declining degree of such protocols. The results of theoretical analysis and simulation show that: (1) in vertical handover, the handover latency of FPMIPv6 is much larger than TPMIPv6 and PMIPv6. But the UDP packet loss rate of FPMIPv6 is smaller than TPMIPv6 and PMIPv6; (2) the handover performance of FPMIPv6-pre and TPMIPv6 much depend on MN's residence time in signal overlapped area.
    Preview · Conference Paper · Jun 2010
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    Jiao Zhang · Yujun Zhang · Hanwen Zhang · Yi Sun · Zhongcheng Li
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    ABSTRACT: Trust relationship among multiple domains is the basis for inter-domain fast authentication. This paper proposes a fast authentication method combining inter-domain trust relationship for wireless mobile IPv6 networks. In order to implement inter-domain trust relationship, a dynamic trust maintenance mechanism is designed. Based on Combined Public Key (CPK) algorithm, a new signature and verification scheme is applied to accelerate the authentication process. This scheme supports the proposed trust-based mutual authentication between mobile node and the access network. Theoretical analysis and numerical results show that the proposed method is more effective in reducing authentication delay and signaling overhead. Additionally, the proposed method is proven to be tolerant of existential forgery and man-in-the-middle attacks.
    Preview · Conference Paper · Jan 2009
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    Hanwen Zhang · Chao Ma · Yujun Zhang · Zhongcheng Li
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    ABSTRACT: In MIPv6, the home agent (HA) is the key entity to ensure a mobile node¿s (MN) reachability. A single HA on the home link will become a performance bottleneck and single point of failure. This paper proposes a Multiple HA Deployment Scheme (MHADS) comprising a dynamic load balancing mechanism based on active overloading prevention and a MN-unaware fault-tolerance mechanism. The results of simulation show that, MHADS can be more efficient in enhancing service availability and improving system performance as compared with the previous mechanisms, when the home link is under different load situations as well as in the presence of HA failure.
    Preview · Conference Paper · Dec 2008
  • Hanwen Zhang · Yujun Zhang · Chao Ma · Yi Sun · Zhongcheng Li
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    ABSTRACT: In MIPv6, the home agent (HA) is the key entity to ensure a mobile nodepsilas (MN) reachability. A single HA on the home link will become a performance bottleneck. In order to enhance service availability and improve system performance, it is necessary to configure multiple HAs on the home link and efficiently balance load among these HAs. This paper proposes a dynamic multiple HA load balancing mechanism based on active overload prevention (DHALAOP). The solution actively prevents HA from overloading in advance, rather than just passively transferring excess load among HAs as previous load balancing mechanisms do. A novel dynamic weight load evaluation algorithm is introduced to provide the basis for optimal load balancing decision. In addition, DHALAOP utilizes single HA mirror image and load slicing scheme to achieve the transparency of load balancing and eliminate unnecessary additional overhead. The theoretical analysis results show that DHALAOP can be more efficient in enhancing service availability and improving system performance as compared with the previous mechanisms. At the same time it introduces a lower signaling cost.
    No preview · Conference Paper · Aug 2008
  • Ye Tian · Yujun Zhang · Hanwen Zhang · Zhongcheng Li
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    ABSTRACT: Access authentication is very important for deploying mobile IPv6 networks. In this paper, we design a two-level hierarchical identity-based signature scheme, based on which we propose a new hierarchical authentication scheme for mobile IPv6 networks. Our solution adopts multi-level network access identifier (NAI) as public key, which simplifies key management in wireless mobile environment. The handover procedure integrating authentication is also cut down by our hierarchical solution. And our solution accomplishes mutual authentication between terminal and network. We propose the handover latency analytical model to evaluate handover latency. The results show that our solution is more efficient than others, especially when a terminal is far away from its home domain and moves frequently. Security analysis shows that the proposed scheme is sufficient for privacy and unforgeability. An extended version for access authentication in multi-hierarchical mobile IPv6 networks is discussed.
    No preview · Conference Paper · Jul 2006