Browsing by Author "Osipkov, Ivan"

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    Fighting Freeloaders in Decentralized P2P File Sharing Systems
    (2004-01-14) Osipkov, Ivan; Kim, Yongdae; Tripathi, Anand
    Currently used P2P file-sharing systems such as Gnutella suffer from a freeloading problem due to absence of enforcible decentralized mechanism to motivate peers to provide services to others. Freeloading leads to a defacto centralized system that is susceptible to DoS attacks and provides poor service to its participants. In this paper, we propose a decentralized mechanism that avoids on-line polling and forces peers to contribute their bandwidth to the system. We discuss additional positive properties of the model and, finally, discuss how to deal with collusion and Sybil attacks.
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    Robustness and Security in a Mobile-Agent based Network Monitoring System
    (2004-01-13) Tripathi, Anand; Koka, Muralidhar; Karanth, Sandeep; Osipkov, Ivan; Talkad, Harsha; Ahmed, Tanvir; Johnson, David; Dier, Scott
    In Konark, a network monitoring system based on mobile-agents,agents can communicate witheach other to perform system-wide correlation of data.To minimize management efforts, our system incorporatesmechanisms to detect and self-recover frominternal failures in a decentralized and scalable fashion.In this paper, we discuss the mechanisms for self-recoveryachievedby using the same mechanisms as those used for monitoringcomputing resources in thenetwork.Self-monitoring of Konark also provides all the features ofnetwork monitoring,such as dynamic extensibility, active monitoring, andonline-correlation of data.The security mechanisms of Konark are also discussed.This work demonstrates that mobile-agent based approach is aviable alternative forbuilding robust and secure network monitoring systems. Keywords: Self-Monitoring and Recovery, Network monitoring,Mobile agents, Multi-agent systems, Mobile code,Monitoring system security, Distributed Event Communication