Hybrid P2P System Research Articles

Search in a hybrid P2P system using a node map formed by a self-organising map

We propose a hybrid P2P information search system that combines: 1) the idea that a searcher searches not information itself but people who have KANSEI (human sensitivity) well fitted to the searcher; 2) a P2P network on which we can build a scalable information search system; 3) a folksonomy, which is a system that allows users to classify information by themselves, to quickly and reliably obtain the desired information from on the network. The main characteristic of the proposed system is that it produces a two-dimensional map visualising the KANSEI information of all nodes by a self-organising map, and then utilises the map for searches. The simulation results show that the proposed system provides balanced opportunities from which we obtain our desired information and other unknown information, in comparison with a search method that conducts searches directly in higher-dimensional space and a random search method.

Impacts of Selfish Behaviors on the Scalability of Hybrid Client–Server and Peer-to-Peer Caching Systems

This paper considers a hybrid peer-to-peer (p2p) system, a dynamic distributed caching system with an authoritative server dispensing contents only if the contents fail to be found by searching an unstructured p2p system. We study the case when some peers may not be fully cooperative in the search process and examine the impact of various noncooperative behaviors in the aspect of scalability, more specifically average server load and average peer load as the peer population size increases. We categorize selfish peers into three classes: impatient peers that directly query the server without searching the p2p system, non-forwarders that refuse to forward query requests, and non-resolvers that refuse to share contents. It is shown that in the hybrid p2p system, impatient and/or non-forwarding behaviors prevent the system from scaling well because of the high server load, while the system scales well under the non-resolving selfish peers. Our study implies that the hybrid p2p system does not mandate an incentive mechanism for content sharing, which is in stark contrast to unstructured p2p systems, where incentivizing peers to share contents is known to be a key factor for the system's scalability.

A novel hybrid P2P and cloud storage system for retrievability and privacy enhancement

This paper presents a novel fountain code-based hybrid P2P and cloud storage system. While most cloud storage systems guarantees data retrievability of high level, they may be vulnerable to data privacy since the stored data may be exposed to others by accident or design. On the other hand, P2P storage system keeps any peer from accessing the whole data by dividing the data into small pieces and distributing them to multiple participating peers, but may degrade data retrievability due to unstable peers. The proposed hybrid storage system attempts to enhance data retrievability and privacy by effectively distributing fountain encoded symbols to cloud server system and participating peers. It is demonstrated that the proposed hybrid storage system achieves the desired level of data retrievability with a short upload time, and enhance privacy by preventing others from reading the contents.

IP2P: a peer-to-peer system for mobile devices

Peer-to-peer communications is a major trend in wireless Internet. In a P2P system, the calling peer must identify the network address of the called peer before establishing a P2P connection. This article proposes iP2P, a hybrid P2P system for mobile devices. iP2P utilizes the short message service as the control protocol to identify the address of the called peer. Our approach provides an efficient identification mechanism without the requirement for the maintenance of a centralized registrar server in a hybrid P2P system. We also show how iP2P can integrate effectively with the existing network address translation traversal mechanisms to solve the private IP address issue.

The expansion and mixing time of skip graphs with applications

We prove that with high probability a skip graph contains a 4-regular expander as a subgraph and estimate the quality of the expansion via simulations. As a consequence, skip graphs contain a large connected component even after an adversarial deletion of nodes. We show how the expansion property can be used to sample a node in the skip graph in a highly efficient manner. We also show that the expansion property can be used to load balance the skip graph quickly. Finally, it is shown that the skip graph could serve as an unstructured P2P system, making it a good candidate for a hybrid P2P system.