LENS: LEveraging social Networking and trust to prevent Spam transmission

Spam is still an open problem from the network operator’s perspective. The common state-of-the-art strategy to place filters against spam is at the recipient’s edge. Although this strategy largely solves the spam problem from the user’s perspective – false positives/negatives may still exist – it cannot prevent spam from traversing the Internet. Consequently, with nowadays around 200 billion spam/day, spam continues to consume large amounts of Internet bandwidth and provokes non-negligible financial loss to network operators. Therefore it becomes imperative to mitigate spam much earlier than at the recipient’s edge. This goal has been recently accomplished only partially by placing filters at the edge of a social circle within a social network. In this project we introduce LENS, a novel spam protection system based on the social networking paradigm, which further mitigates spam beyond users' social circles. The key idea of this paradigm in LENS is to let users select legitimate and authentic users, called Gatekeepers (GKs), from outside their social circle and within pre-defined social distances. Unless a GK vouches for the emails of potential senders from outside the social circle of a particular recipient, those e-mails are prevented from transmission. This way LENS drastically reduces the consumption of Internet bandwidth by spam to control messages only.