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[Author] Yohei KATAYAMA(3hit)

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  • iAuth: An HTTP Authentication Framework Integrated into HTML Forms

    Takeru INOUE  Yohei KATAYAMA  Hiroshi SATO  Noriyuki TAKAHASHI  

     
    PAPER-Internet

      Vol:
    E94-B No:2
      Page(s):
    466-476

    Current Web authentication frameworks have well-known weaknesses. HTTP provides an access authentication framework, but it is rarely used because it lacks presentational control. Forms and cookies, which are most commonly used, have the long-standing privacy issue raised by tracking. URI sessions, which are used in some mobile services like i-mode 1.0, disclose session identifiers unintentionally. This paper proposes iAuth, which integrates better parts of the existing frameworks and fixes their problems; iAuth allows servers to provide log-in forms, and introduces a session header to avoid servers' tracking and unintentional disclosure. Since iAuth has backward compatibility with the major legacy browsers, developers can freely introduce iAuth into their Web sites or browsers as needed. Experiments confirm its correct operation; an iAuth server is shown to support not only an iAuth client but major legacy browsers. We believe that iAuth will resolve the long-standing issues in Web authentication.

  • Scalability Analysis of Source Routing Multicast for Huge Numbers of Groups

    Yohei KATAYAMA  Takeru INOUE  Noriyuki TAKAHASHI  Ryutaro KAWAMURA  

     
    PAPER

      Vol:
    E96-B No:11
      Page(s):
    2784-2794

    Source routing multicast has been gathering much more attention rather than traditional IP multicast, since it is thought to be more scalable in terms of the number of groups at the cost of higher traffic loads. This paper introduces a mathematical framework to analyze the scalability of source routing multicast and IP multicast by leveraging previous multicast studies. We first analyze the amount of data traffic based on the small-world nature of networks, and show that source routing multicast can be as efficient as IP multicast if a simple header fragmentation technique (subgrouping) is utilized. We also analyze scalability in terms of group numbers, which are derived under the equal budget assumption. Our analysis shows that source routing multicast is competitive for low bit-rate streams, like those in the publish/subscribe service, but we find some factors that offset the advantage. This is the first work to analytically investigate the scalability of source routing multicast.

  • Design and Implementation of Network Virtualization Management System

    Yohei KATAYAMA  Takehito YAMAMOTO  Yukio TSUKISHIMA  Kazuhisa YAMADA  Noriyuki TAKAHASHI  Atsushi TAKAHARA  Akihiro NAKAO  

     
    PAPER

      Vol:
    E97-B No:11
      Page(s):
    2286-2301

    Due to the recent network service market trends, network infrastructure providers must make their network infrastructures tolerant of network service complexity and swift at providing new network services. To achieve this, we first make a design decision for the single domain network infrastructure in which we use network virtualization and separate the network service control and management from the network infrastructure and leave the resource connectivity control and management in the network infrastructure so that the infrastructure can maintain simplicity and the network service can become complex and be quickly provided. Along with the decision, we construct an architecture of the network infrastructure and a network management model. The management model defines a slice as being determined by abstracted resource requirements and restructures the roles and planes from the viewpoint of network infrastructure usability so that network service requesters can manage network resources freely and swiftly in an abstract manner within the authorities the network infrastructure operator provides. We give the details of our design and implementation for a network virtualization management system along with the model. We deployed and evaluated our designed and implemented management system on the Japan national R&E testbed (JGN-X) to confirm the feasibility of our management system design and discuss room for improvement in terms of response time and scalability towards practical use. We also investigated certain cases of sophisticated network functions to confirm that the infrastructure can accept these functions without having to be modified.