The Experts below are selected from a list of 477 Experts worldwide ranked by ideXlab platform

Leonard G. C. Hamey - One of the best experts on this subject based on the ideXlab platform.

  • Poster Presentation UniServe Science Improving Learning Outcomes Symposium Proceedings 96 Using the Security Protocol Game to teach computer network security
    2014
    Co-Authors: Leonard G. C. Hamey
    Abstract:

    Abstract: The Security Protocol Game is a highly interactive game for teaching secure data communications protocols. Students use the game to simulate security protocols and explore possible attacks against them. The power of the game lies in the representation it provides for secret and public key cryptography – a unique combination of game rules and playing pieces has been devised that accurately represents the mathematical capabilities of cryptographic systems. Using pen and paper, envelopes and printed game pieces, students can simulate a wide range of computer network security protocols including well-known protocols such as SSL and pretty good privacy. Such simulations enable students to gain a deep understanding of how the protocols operate and how protocol design affects security of the protocol. Student response to the game is positive and engaging. It has been successfully used with both information technology students and management students. This paper presents the game briefly followed by analysis and discussion of a recent survey of student response to the game

  • Using the Security Protocol Game to teach computer network security
    2012
    Co-Authors: Leonard G. C. Hamey
    Abstract:

    The Security Protocol Game is a highly interactive game for teaching secure data communications protocols. Students use the game to simulate security protocols and explore possible attacks against them. The power of the game lies in the representation it provides for secret and public key cryptography – a unique combination of game rules and playing pieces has been devised that accurately represents the mathematical capabilities of cryptographic systems. Using pen and paper, envelopes and printed game pieces, students can simulate a wide range of computer network security protocols including well-known protocols such as SSL and pretty good privacy. Such simulations enable students to gain a deep understanding of how the protocols operate and how protocol design affects security of the protocol. Student response to the game is positive and engaging. It has been successfully used with both information technology students and management students. This paper presents the game briefly followed by analysis and discussion of a recent survey of student response to the game.

  • Teaching Secure Communcation Protocols Using a Game Representation
    Proceedings of the Fifth Australasian Computing Education Conference, 2003
    Co-Authors: Leonard G. C. Hamey
    Abstract:

    The Security Protocol Game is a highly visual and interactive game for teaching secure data communications protocols. Students use the game to simulate protocols and explore possible attacks against them. The power of the game lies in the representation of secret and public key cryptography. Specifically, the game provides representations for plain text and encrypted messages, message digests, digital signatures and cryptographic keys. Using these representations, students can construct public key certificates and perform multiple encryption, tunnelling and encrypted key transmission. They can simulate a wide range of protocols including authentication, key exchange and blind signature protocols. Application protocols such as Transport Layer Security and pretty good privacy can be simulated in detail. The game clearly reveals the key issues of confidentiality, integrity, authentication and non-repudiation in secure data communications. Used as a small group learning activity, students gain a deep understanding of protocol design and operation issues. The game is suitable for use in tertiary and professional education courses for managers and information technology students at all levels.

Alex Arenas - One of the best experts on this subject based on the ideXlab platform.

  • Models of social networks based on social distance attachment
    Physical Review E, 2004
    Co-Authors: Marián Boguñá, Romualdo Pastor-satorras, Albert Díaz-guilera, Alex Arenas
    Abstract:

    We propose a class of models of social network formation based on a mathematical abstraction of the concept of social distance. Social distance attachment is represented by the tendency of peers to establish acquaintances via a decreasing function of the relative distance in a representative social space. We derive analytical results (corroborated by extensive numerical simulations), showing that the model reproduces the main statistical characteristics of real social networks: large clustering coefficient, positive degree correlations, and the emergence of a hierarchy of communities. The model is confronted with the social network formed by people that shares confidential information using the pretty good privacy (PGP) encryption algorithm, the so-called web of trust of PGP.

  • Macro- and micro-structure of trust networks
    arXiv: Disordered Systems and Neural Networks, 2002
    Co-Authors: X. Guardiola, Albert Díaz-guilera, Alex Arenas, Roger Guimerà, D. Streib, Luís A. Nunes Amaral
    Abstract:

    A challenging problem in the social sciences is the characterization of the formation of ``social capital''. It is believed that societies with more social capital are more democratic and economically developed than societies with little social capital. However, social capital is a concept hard to quantify and measure in a ``real-word'' context. Here, we take advantage of an existing "web of trust'' between users of the "pretty-good-privacy" (PGP) encryption algorithm, which is used in digital communication to ``sign'' documents so that the recipient knows for sure who the author is. Our analysis reveals the coexistence in the web of trust of a macro scale-free structure with micro strongly-connected cells in a complex network. We also show that when this network is intentionally attacked the scale-free structure rapidly disintegrates and that the resulting network is partitioned into a large number of small strongly-connected cells that are resilient to the intentional attack.

Guangchi Liu - One of the best experts on this subject based on the ideXlab platform.

  • Trust Assessment in Online Social Networks
    arXiv: Social and Information Networks, 2019
    Co-Authors: Guangchi Liu, Qing Yang, Honggang Wang, Alex X. Liu
    Abstract:

    Assessing trust in online social networks (OSNs) is critical for many applications such as online marketing and network security. It is a challenging problem, however, due to the difficulties of handling complex social network topologies and conducting accurate assessment in these topologies. To address these challenges, we model trust by proposing the three-valued subjective logic (3VSL) model. 3VSL properly models the uncertainties that exist in trust, thus is able to compute trust in arbitrary graphs. We theoretically prove the capability of 3VSL based on the Dirichlet-Categorical (DC) distribution and its correctness in arbitrary OSN topologies. Based on the 3VSL model, we further design the AssessTrust (AT) algorithm to accurately compute the trust between any two users connected in an OSN. We validate 3VSL against two real-world OSN datasets: Advogato and pretty good privacy (PGP). Experimental results indicate that 3VSL can accurately model the trust between any pair of indirectly connected users in the Advogato and PGP.

  • INFOCOM - OpinionWalk: An efficient solution to massive trust assessment in online social networks
    IEEE INFOCOM 2017 - IEEE Conference on Computer Communications, 2017
    Co-Authors: Guangchi Liu, Qing Yang, Honggang Wang, Qi Chen, Binhai Zhu, Wei Wang
    Abstract:

    Massive trust assessment (MTA) in an Online Social Network (OSN), i.e., computing the trustworthiness of all users in the network, is crucial in various OSN-related applications. Existing solutions are either too slow or inaccurate in addressing the MTA problem. We propose the OpinionWalk algorithm that accurately and efficiently conducts MTA in an OSN. OpinionWalk models trust by the Dirichlet distribution and uses a matrix to represent the direct trust relations among users. From the perspective of a user, other users' trustworthiness are stored in a column vector that is iteratively updated when the algorithm “walks” through the network, in a breadth-first search manner. We identify the overlapping subproblems property in MTA and prove OpinionWalk is a more efficient solution. The accuracy and execution time of OpinionWalk are evaluated and compared to benchmark algorithms including EigenTrust, TrustRank, MoleTrust, TidalTrust and AssessTrust, using two real-world datasets (Advogato and pretty good privacy). Experimental results indicate that OpinionWalk is an efficient and accurate solution to MTA, compared to previous algorithms.

Wei Wang - One of the best experts on this subject based on the ideXlab platform.

  • INFOCOM - OpinionWalk: An efficient solution to massive trust assessment in online social networks
    IEEE INFOCOM 2017 - IEEE Conference on Computer Communications, 2017
    Co-Authors: Guangchi Liu, Qing Yang, Honggang Wang, Qi Chen, Binhai Zhu, Wei Wang
    Abstract:

    Massive trust assessment (MTA) in an Online Social Network (OSN), i.e., computing the trustworthiness of all users in the network, is crucial in various OSN-related applications. Existing solutions are either too slow or inaccurate in addressing the MTA problem. We propose the OpinionWalk algorithm that accurately and efficiently conducts MTA in an OSN. OpinionWalk models trust by the Dirichlet distribution and uses a matrix to represent the direct trust relations among users. From the perspective of a user, other users' trustworthiness are stored in a column vector that is iteratively updated when the algorithm “walks” through the network, in a breadth-first search manner. We identify the overlapping subproblems property in MTA and prove OpinionWalk is a more efficient solution. The accuracy and execution time of OpinionWalk are evaluated and compared to benchmark algorithms including EigenTrust, TrustRank, MoleTrust, TidalTrust and AssessTrust, using two real-world datasets (Advogato and pretty good privacy). Experimental results indicate that OpinionWalk is an efficient and accurate solution to MTA, compared to previous algorithms.

Kazuo Toraichi - One of the best experts on this subject based on the ideXlab platform.

  • A public key cryptography-based security enhanced mail gateway with the mailing list function
    1999 IEEE Pacific Rim Conference on Communications Computers and Signal Processing (PACRIM 1999). Conference Proceedings (Cat. No.99CH36368), 1
    Co-Authors: Kazuki Katagishi, T. Asami, Y. Ebihara, Tetsuo Sugiyama, Kazuo Toraichi
    Abstract:

    When sending corporate secrets by electronic mail (e-mail), care must be taken to protect the security of the information against the various kinds of illicit manipulation that can occur on the Internet. We have developed a security enhanced mail gateway (SEMAIL) that ensures the privacy of e-mail messages without requiring users to install new software or learn complicated operating procedures. The SEMAIL system, in which an encryption program PGP (pretty good privacy) is used, is available for both POP3-based Unix mails and PC-LAN-based ones.

  • PGP-based security enhanced mail gateway (SEMAIL) with POP authentication for large scale organizations
    2003 IEEE Pacific Rim Conference on Communications Computers and Signal Processing (PACRIM 2003) (Cat. No.03CH37490), 1
    Co-Authors: S. Chihara, Kazuki Katagishi, T. Asami, A. Vasilache, Hitomi Murakami, Kazuo Toraichi
    Abstract:

    In this paper, we propose a security tool for security enhanced mail gateway (SEMAIL). SEMAIL is a mail server package designed to provide PGP (pretty good privacy)-based e-mail security to all the members of an organization. SEMAIL is attempting to solve the problems incurred by implementing PGP in large scale organizations. In this paper we introduce a POP before SMTP implementation that authenticates users before sending messages using SMTP. POP before SMTP for SEMAIL is designed to perform user level authentication in such way that the number of "receive before send" requests for the purpose of authentication is drastically reduced. Moreover, it overcomes problems induced by the ordinary implementation in a DHCP environment. As a result, SEMAIL with POP before SMTP is expected to become more secure and practical for large scale organizations.