Abstract

I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required nal revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii Centrally controlled search engines will not be sucient and reliable for index-ing and searching the rapidly growing World Wide Web in near future. A better solution is to enable the Web to index itself in a decentralized manner. Existing distributed approaches for ranking search results do not provide exible searching, complete results and ranking with high accuracy. This thesis presents a decen-tralized Web search mechanism, named DEWS, which enables existing webservers to collaborate with each other to form a distributed index of the Web. DEWS can rank the search results based on query keyword relevance and relative impor-tance of websites in a distributed manner preserving a hyperlink overlay on top of a structured P2P overlay. It also supports approximate matching of query keywords