Digging into IP Flow Records with a Visual Kernel Method - Computational Intelligence in Security for Information Systems - page 100

A Secure and Efficient Searching Scheme for Trusted
Nodes in a Peer-to-Peer Network
Jaydip Sen
TCS Innovation Labs, Tata Consultancy Services Ltd.,
Bengal Intelligent Park, Salt Lake Electronics Complex, Kolkata - 700091, India
[e-mail]
Abstract. The existing search mechanisms for peer-to-peer (P2P) networks
have several problems such as fake content distribution, free riding, white-
washing and poor search scalability. Although, researchers have proposed
several trust management and semantic community-based mechanisms for
combating free riding and distribution of malicious contents, most of these
schemes lack scalability due to their high computational, communication and
storage overhead. This paper presents a trust management scheme for P2P net-
works that utilizes topology adaptation by constructing an overlay of trusted
peers where the neighbors are selected based on their trust ratings and content
similarities. It also increases the search efficiency by taking advantage of the
implicit semantic community structures formed as a result of topology adapta-
tion since most of the queries are resolved within the community of trustworthy
peers. Simulation results demonstrate that the proposed scheme provides effi-
cient searching to good peers while penalizing the malicious peers by increasing
their search times.
Keywords: P2P network, topology adaptation, trust management, semantic
community, malicious peer.
1 Introduction
The term peer-to-peer (P2P) system encompasses a broad set of distributed applica-
tions which allow sharing of computer resources by direct exchange between systems.
The goal of a P2P system is to aggregate resources available at the edge of Internet
and to share it cooperatively among users. Specially, the file sharing P2P systems
have become popular as a new paradigm for information exchange among large num-
ber of users in Internet. They are more robust, scalable, fault tolerant and offer better
availability of resources. Depending on the presence of a central server, P2P systems
can be classified as centralized or decentralized [1]. In decentralized architecture, both
resource discovery and download are distributed. Decentralized P2P application may
be further classified as structured or unstructured network. In structured network,
there is a restriction on the placement of content and network topology. In
unstructured P2P network, however, placement of content is unrelated to topology.
Unstructured P2P networks perform better than their structured counterpart in dy-
namic environment. However, they need efficient search mechanisms and suffer from