direkt zum Inhalt springen

direkt zum Hauptnavigationsmenü

Sie sind hier

TU Berlin

Inhalt des Dokuments

Peer-to-Peer Computing

Peer-to-peer computing is an interesting networking paradigm as it offers a high degree of scalability by exploiting the resources of the participants and avoids single-points of failures. Due to these desirable properties, peer-to-peer computing plays a crucial role in many networking applications beyond file-sharing, and the underlying ideas are also discussed as a design principle for the future Internet. Our research is concerned with the question of whether peer-to-peer is mature enough to step outside its "comfort zone". We conduct measurements of state-of-the-art peer-to-peer networks such as Kad and investigate the robustness, e.g., to Sybil attacks or selfish behavior. For example, we implemented the proof-of-concept BitTorrent client "BitThief" which provides evidence that despite the tit-for-tat incentive mechanism, free-riding is possible in BitTorrent. We develop algorithms to improve the performance of peer-to-peer systems: we devise peer-to-peer networks which are robust to worst-case churn (see e.g., our IPTPS paper), which allow for efficient joins and leaves (see e.g., our SHELL system at ICALP), or which are robust to denial of service attacks (see e.g., our Chameleon system at SPAA). Some of these algorithms were successfully implemented in the online storage tool Wuala and the streaming tool Streamforge, two Swiss startups.

Selected Publications

Locher, Thomas and Schmid, Stefan and Wattenhofer, Roger (2011). eDonkey and eMule's Kad: Measurements and Attacks. Fundamenta Informaticae. IOS Press, 383–403.


Kuhn, Fabian and Schmid, Stefan and Wattenhofer, Roger (2010). Towards Worst-Case Churn Resistant Peer-to-Peer Systems. Distributed Computing Journal (DC). Springer, 249–267.


Jacob, Riko and Richa, Andréa and Scheideler, Christian and Schmid, Stefan and Täubig, Hanjo (2009). A Polylogarithmic Time Algorithm for Distributed Self-Stabilizing Skip Graphs. 28th ACM Symposium on Principles of Distributed Computing (PODC), 131–140.


Baumgart, Matthias and Scheideler, Christian and Schmid, Stefan (2009). A DoS-Resilient Information System for Dynamic Data Management. 21st ACM Symposium on Parallelism in Algorithms and Architectures (SPAA), 300–309.


Scheideler, Christian and Schmid, Stefan (2009). A Distributed and Oblivious Heap. 36th International Colloquium on Automata, Languages and Programming (ICALP). Springer, 571–582.


Locher, Thomas and Meier, Remo and Schmid, Stefan and Wattenhofer, Roger (2007). Push-to-Pull Peer-to-Peer Live Streaming. 21st International Symposium on Distributed Computing (DISC). Springer, 388–402.


Locher, Thomas and Moor, Patrick and Schmid, Stefan and Wattenhofer, Roger (2006). Free Riding in BitTorrent is Cheap. 5th Workshop on Hot Topics in Networks (HotNets), 85–90.


Grolimund, Dominik and Meisser, Luzius and Schmid, Stefan and Wattenhofer, Roger (2006). Cryptree: A Folder Tree Structure for Cryptographic File Systems. 25th IEEE Symposium on Reliable Distributed Systems (SRDS), 189–198.


Locher, Thomas and Schmid, Stefan and Wattenhofer, Roger (2006). eQuus: A Provably Robust and Locality-Aware Peer-to-Peer System. 6th IEEE International Conference on Peer-to-Peer Computing (P2P), 3–11.


Moscibroda, Thomas and Schmid, Stefan and Wattenhofer, Roger (2006). On the Topologies Formed by Selfish Peers. 25th Annual Symposium on Principles of Distributed Computing (PODC), 133–142.


Kuhn, Fabian and Schmid, Stefan and Wattenhofer, Roger (2005). A Self-Repairing Peer-to-Peer System Resilient to Dynamic Adversarial Churn. 4th International Workshop on Peer-To-Peer Systems (IPTPS). Springer, 13–23.


Zusatzinformationen / Extras

Quick Access:

Schnellnavigation zur Seite über Nummerneingabe

Auxiliary Functions