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

Towards Worst-Case Churn Resistant Peer-to-Peer Systems
Citation key KSW-TWCCRP2PS-10
Author Kuhn, Fabian and Schmid, Stefan and Wattenhofer, Roger
Pages 249–267
Year 2010
ISSN 0178-2770
DOI http://dx.doi.org/10.1007/s00446-010-0099-z
Journal Distributed Computing Journal (DC)
Volume 22
Number 4
Month May
Publisher Springer
Abstract Until now, the analysis of fault tolerance of peer-to-peer systems usually only covers random faults of some kind. Contrary to traditional algorithmic research, faults as well as joins and leaves occurring in a worst-case manner are hardly considered. In this article, we devise techniques to build dynamic peer-to-peer systems which remain fully functional in spite of an adversary who continuously adds and removes peers. We exemplify our algorithms on hypercube and pancake topologies and present a system which maintains small peer degree and network diameter.
Link to publication Download Bibtex entry

Zusatzinformationen / Extras

Quick Access:

Schnellnavigation zur Seite über Nummerneingabe

Auxiliary Functions