Peer-to-Peer (p2p) networks are the latest addition to the already large distributed systems family. With a strong emphasis on self-organization, decentralization and autonomy of the participating nodes, p2p-networks tend to be more scalable, robust and adaptive than other forms of distributed systems. The much-publicized success of p2pnetworks for file-sharing and cycle-sharing have resulted i...

Peer-to-Peer (P2P) systems are emerging as a “new” form of distributed computing with a strong emphasis on selforganization, decentralization and autonomy of the participating nodes. Self-organization, autonomy and decentralization allow for highly adaptive, robust and scalable networks making P2P an increasingly interesting way to design distributed systems. Unfortunately it is still very diff...

Abstract: Today, most peer-to-peer networks are specialised for sharing files, mostly video and audio files. In this paper we describe a peer-to-peer network we are currently implementing. It connects webcams and allows users to search for online pictures and video-/audiostreams by keyword and by location. Peer-to-peer technology is used for the self-organising network so that no central servic...

Existing Internet systems implement anonymity at the application layer or through centralized components. A robust, decentralized infrastructure that anonymizes any Internet traffic could benefit a wide array of existing protocols and systems. This anonymous network layer could seamlessly replace the current communications channel, and it could continue to offer anonymity and availability even ...

Society’s increasing reliance on digital communication networks is creating unprecedented opportunities for wholesale surveillance and censorship. This thesis investigates the use of public networks such as the Internet to build robust, private communication systems that can resist monitoring and attacks by powerful adversaries such as national governments. We sketch the design of a censorship-...

“Flooding” is a fundamental operation in unstructured Peer-to-Peer (P2P) file sharing systems, such as Gnutella. Although it is effective in content search, flooding is very inefficient because it results in a great amount of redundant messages. Our study shows that more than 70% of the generated messages are redundant for a flooding with a TTL of 7 in a moderately connected network. Existing e...