Evaluating Reputation Systems for Document Authenticity

Few P2P file-sharing networks developed to date have successfully provided mechanisms to ensure the authenticity of documents delivered to clients. For example, when a P2P client receives a hit for “Origin of Species,” the client currently has no assurance that the corresponding downloaded document is an authentic copy of Charles Darwin’s work. The document could be a “decoy” and could contain the content of the book by Charles Darwin with several key passages altered. The document might even be a different work entirely that advocates creationism. Even worse, the client has no way to tell if the downloaded document might be a newly deployed virus. We call the problem of determining whether a document is authentic the document authenticity problem.