Controlling file distribution in Winny network through index poisoning

Peer-to-Peer (P2P) file sharing networks have witnessed dramatic increase in popularity for the past few years. In order to meet the demand of users, most P2P file sharing networks have been primarily focusing on improving transmission efficiency and network scalability. However, these networks do not usually have management mechanisms for distributing files in general. Consequently, copyright infringements in P2P file sharing networks have become prevalent. In order to prevent illegal file distribution, several anti-P2P companies have controlled the file distribution by index poisoning. Although index poisoning aims to obfuscate uses by diffusing a lot of dummy metadata in P2P networks, its effects have not been well studied yet. In this paper, we apply index poisoning to a Winny network, one of the most popular P2P file sharing networks in Japan, to control the file distribution. Our evaluation includes index poisoning in a live Winny network composed of over 100,000 active peers. The result shows that our proposed method can decrease the number of query hits to less than 0.004% compared to the case without our control, and that index poisoning is effective to control a small number of files. However, the result also shows that the index poisoning could cause a serious damage on a Winny network, when many files are under our control simultaneously.