Impact of peer incentives on the dissemination of polluted content

Recent studies have reported a new form of malicious behavior in file-sharing Peer-to-Peer systems: content pollution. The dissemination of polluted content in a P2P system has the detrimental effect of reducing content availability, and ultimately, decreasing the confidence of users in such systems. Two potential strategies for polluting P2P content are decoy insertion, which consists of injecting corrupted copies of a file into the system, and hash corruption, which consists of injecting a corrupted file with the same hash code as a non-corrupted one. Polluted content disseminates through P2P networks because users typically do not delete the corrupted files that they download.This paper investigates the effectiveness of peer incentives to delete corrupted files in reducing the dissemination of polluted content, considering the two aforementioned pollution mechanisms. Our simulation results show that the effectiveness of incentives is highly dependent on the pollution mechanism. We show that for a pollution dissemintation techinique called hash corruption, only effective incentive mechanisms are able to avoid spreading of polluted content.