Karlo Berket

PKI-based security for peer-to-peer information sharing

Freeflow of information is the feature that has made peer-to-peer information sharing applications popular. However, this very feature holds back the acceptance of these applications by the corporate and scientific communities. In these communities it is important to provide confidentiality and integrity of communication and to enforce access control to shared resources. We present a collection of security mechanisms that can be used to satisfy these security requirements. Our solutions are based on established and proven security techniques and we utilize existing technologies when possible. As a proof of concept, we have developed an information sharing system, called scishare, which integrates a number of these security mechanisms to provide a secure environment for information sharing. This system will allow a broader set of user communities to benefit from peer-to-peer information sharing.

A practical approach to the interGroup protocols

Existing reliable ordered group communication protocols have been developed for local-area networks and do not, in general, scale well to large numbers of nodes and wide-area networks. The InterGroup suite of protocols is a scalable group communication system that introduces an unusual approach to handling group membership, and supports a receiver-oriented selection of service. The protocols are intended for a wide-area network, with a large number of nodes, that has highly variable delays and a high message loss rate, such as the Internet. The levels of the message delivery service range from unreliable unordered to reliable timestamp ordered. We also present a secure group layer that builds on InterGroup to provide SSL-like security for groups.

Improving the bulk data transfer experience

Scientific computations and collaborations increasingly rely on the network to provide high-speed data transfer, dissemination of results, access to instruments, support for computational steering, etc. The Energy Sciences Network is establishing a science data network to provide user driven bandwidth allocation. In a shared network environment, some reservations may not be granted due to the lack of available bandwidth on any single path. In many cases, the available bandwidth across multiple paths would be sufficient to grant the reservation. In this paper we investigate how to utilise the available bandwidth across multiple paths in the case of bulk data transfer.

Overview of the InterGroup Protocols

Existing reliable ordered group communication protocols have been developed for local-area networks and do not, in general, scale well to large numbers of nodes and wide-area networks. The InterGroup suite of protocols is a scalable group communication system that introduces a novel approach to handling group membership, and supports a receiver-oriented selection of service. The protocols are intended for a wide-area network, with a large number of nodes, that has highly variable delays and a high message loss rate, such as the Internet. The levels of the message delivery service range from unreliable unordered to reliable group timestamp ordered.

Peer-to-peer I/O (P2PIO) protocol specification Version 0.6

Todays distributed systems require simple and powerful resource discovery queries in a dynamic environment consisting of a large number of resources spanning many autonomous administrative domains. The distributed search problem is hard due to the variety of query types, the number of resources and their autonomous, partitioned and dynamic nature. We propose a generalized resource discovery framework that is built around an application level messaging protocol called Peer-to-Peer I/O (P2PIO). P2PIO addresses a number of scalability problems in a general way. It provides flexible and uniform transport-independent resource discovery mechanisms to reduce both the client and network burden in multi-hop P2P systems.