Peer-to-peer systems have reached a widespread use, ranging from academic and industrial applications to home entertainment. The key advantage of this paradigm lies in its scalability and flexibility, consequences of the participants sharing their resources for the common welfare. Security in such systems is a desirable goal. For example, when mission-critical operations or bank transactions ar...

“Peer-to-peer” systems like Napster and Gnutella have recently become popular for sharing information. In this paper, we study the relevant issues and tradeoffs in designing a scalable P2P system. We focus on a subset of P2P systems, known as “hybrid” P2P, where some functionality is still centralized. (In Napster, for example, indexing is centralized, and file exchange is distributed.) We mode...

Peer-to-Peer (P2P) systems allow participants to share their computational, storage, and networking resources to the benefit of every participant. Most P2P systems assume that all participants in the system follow the protocols and observe the system’s fair use policies. However, in a system with open or loosely controlled membership, participants have a self-interest in modifying their behavio...

Modern peer-to-peer systems rely heavily on the willingness of users to distribute files to their peers. A selfish user can choose to download a file and consume resources without uploading in return. This form of free-riding plagues all currently deployed systems. We present a protocol for a BitTorrent-like system (i.e., in which only one file is being shared) that strongly discourages peers f...

We argue that traditional systems engineering (TSE) is inadequate for engineering complex systems. This inadequacy becomes particularly problematic when the system in question is a System of Systems (SoS) whose behaviour depends on how human users of the component systems, anticipating the consequences of their own behaviour, interact with those systems and with each other. Considering its user...

We consider the problem of designing an overlay network and routing mechanism that permits finding resources efficiently in a peer-to-peer system. We argue that many existing approaches to this problem can be modeled as the construction of a random graph embedded in a metric space whose points represent resource identifiers, where the probability of a connection between two nodes depends only o...

Peer-to-peer systems like Napster, Gnutella and Kazaa have recently become popular for sharing information. In this paper, we show how to design peer-to-peer systems within the action systems framework by combining UML diagrams. We present our approach via a case study of stepwise development of a Gnutella-like peer-to-peer system.

Peer-to-Peer (P2P) is a fully distributed communication model in which parties (aka peers) have equivalent functional capabilities in providing each other with data and services. Because they are totally autonomous, peers are independent of other peers in which data they store, in which other peers they interoperate with, and in how they process peers’ service requests. While the cost of partic...