Decentralized peer-to-peer (P2P) resource sharing applications lack a centralized authority that can facilitate peer and resource look-ups and coordinate resource sharing between peers. Instead, peers directly interact and exchange resources with other peers. These systems are often open and do not regulate the entry of peers into the system. Thus, there can be malicious peers in the system who threaten others by offering Trojan horses and viruses disguised as seemingly innocent resources. Several trust-based solutions exist to address such threats; unfortunately there is a lack of design guidance on how these solutions can be integrated into a resource sharing application. In this paper, we describe how two teams of undergraduate students separately integrated XREP, a third-party reputation-based protocol for file-sharing applications, with PACE, our software architecture-based approach for decentralized trust management. This was done in order to construct trust-enabled P2P file-sharing application prototypes. Our observations have revealed that using an architecture-based approach in incorporating trust into P2P resource-sharing applications is not only feasible, but also significantly beneficial. Our efforts also demonstrate both the ease of adoption and ease of use of the PACE-based approach in constructing such trust-enabled decentralized applications.
By Girish Suryanarayana, Mamadou H. Diallo, Justin R. Erenkrantz, Richard N. Taylor, August 2006
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In an ad hoc wireless network where wired infrastructures are not feasible, energy and bandwidth conservation are the two key elements presenting challenges to researchers. Limited bandwidth makes a network easily congested by the control signals of the routing protocol. Routing schemes developed for wired networks seldom consider restrictions of this type. Instead, they assume that the network is mostly stable and that the overhead for routing messages is negligible. Considering these differences between wired and wireless network, it is necessary to develop a wireless routing protocol that limits congestion in the network [1, 5, 8, 9, 10, 11].This paper proposes minor modifications to the existing Ad hoc On Demand Vector (AODV) routing protocol (RFC 3561) in order to restrict congestion in networks during a particular type of Denial of Service (DoS) attack. In addition to this, it incurs absolutely no additional overhead [4]. We describe the DoS attack caused due to Route Request (RREQ) flooding and its implications on existing AODV-driven Mobile Ad hoc Networks (MANET) [2, 14]. To combat this DoS attack, a proactive scheme [12] is proposed. We present an illustration to describe the implications of RREQ flooding on pure AODV and the modified AODV protocols. To quantify the effectiveness of the proposed scheme, we simulated a DoS [6] attack in a mobile environment and study the performance results.
By Dhaval Gada, Rajat Gogri, Punit Rathod, Zalak Dedhia, Nirali Mody, Sugata Sanyal, Ajith Abraham, September 2004
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