Rameez Rahman

Learn More
Distributed systems without a central authority, such as peer-to-peer (P2P) systems, employ incentives to encourage nodes to follow the prescribed protocol. Game theoretic analysis is often used to evaluate incentives in such systems. However, most game-theoretic analyses of distributed systems do not adequately model the repeated interactions of nodes(More)
Most P2P systems that have any kind of incentive mechanism reward peers’ contribution in terms of uploaded volume. Due to the disparity in bandwidth capacity between P2P users on the Internet, the common effect of such mechanisms is that the fastest peers reap the highest benefits. We take a different approach and study how to incentivize cooperation in P2P(More)
BitTorrent is a highly popular peer-to-peer filesharing protocol. Much BitTorrent activity takes place within private virtual communities called “Private Trackers” a server that allows only community members to share files. Many private trackers implement “ratio enforcement” where the tracker monitors the upload and download behaviour of peers. If a peer(More)
Many P2P systems have been designed without taking into account an important factor: a large fraction of Internet users nowadays are located behind a network address translator (NAT) or a firewall, making them unable to accept incoming connections (i.e. unconnectable). Peers suffering from this limitation cannot fully enjoy the advantages offered by the P2P(More)
Cloud computing has become pervasive due to attractive features such as on-demand resource provisioning and elasticity. Most cloud providers are centralized entities that employ massive data centers. However, in recent times, due to increasing concerns about privacy and data control, many small data centers (SDCs) established by different providers are(More)
Many private BitTorrent communities employ Sharing Ratio Enforcement (SRE) schemes to incentivize users to contribute their upload resources. It has been demonstrated that communities that use SRE are greatly oversupplied, i.e., they have much higher seeder-to-leecher ratios than communities in which SRE is not employed. The first order effect of oversupply(More)
Many peer-to-peer file sharing communities implement credit policies to incentivise users to contribute upload resources. Such policies implicitly assume a user model - how the user controlling each peer behaves. We show using an agent-based model that credit policies, based on bandwidth contribution, and a selfish user model, can lead to both(More)
Due to the abundance of attractive services available on the cloud, people are placing an increasing amount of their data online on different cloud platforms. However, given the recent large-scale attacks on users data, privacy has become an important issue. Ordinary users cannot be expected to manually specify which of their data is sensitive, or to take(More)
Third party apps that work on top of personal cloud services, such as Google Drive and Dropbox, require access to the user’s data in order to provide some functionality. Through detailed analysis of a hundred popular Google Drive apps from Google’s Chrome store, we discover that the existing permission model is quite often misused: around two-thirds of(More)
The explosion of freely available media content through BitTorrent file sharing networks over the Internet means that users need guides or recommendations to find the right, high quality, content. Current systems rely on centralized servers to aggregate, rate and moderate metadata for this purpose. We present the design and simulations, using real(More)