2 P2P or Not 2 P2P?

In the hope of stimulating discussion, we present a heuristic decision tree that designers can use to judge the likely suitability of a P2P architecture for their applications. It is based on the characteristics of a wide range of P2P systems from the literature, both proposed and deployed.Comment: 6 pages, 1 figur

Interconnecting DSpace and LOCKSS

Repository managers increasingly use toolkits such as DSpace to manage submission of and access to resources. However, DSpace does not support the highly desirable distributed replication functionality provided by LOCKSS. This paper describes an experiment to seamlessly interconnect DSpace and LOCKSS in a generalisable manner. An experimental prototype confirms that this is indeed possible, and that the interoperation can be efficient within the constraints of the systems

Opal: In Vivo Based Preservation Framework for Locating Lost Web Pages

We present Opal, a framework for interactively locating missing web pages (http status code 404). Opal is an example of in vivo preservation: harnessing the collective behavior of web archives, commercial search engines, and research projects for the purpose of preservation. Opal servers learn from their experiences and are able to share their knowledge with other Opal servers using the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH). Using cached copies that can be found on the web, Opal creates lexical signatures which are then used to search for similar versions of the web page. Using the OAI-PMH to facilitate inter-Opal learning extends the utilization of OAI-PMH in a novel manner. We present the architecture of the Opal framework, discuss a reference implementation of the framework, and present a quantitative analysis of the framework that indicates that Opal could be effectively deployed

The UK LOCKSS Pilot Programme: A Perspective from the LOCKSS Technical Support Service

Over the last decade libraries have increasingly shifted journal access from print to digital. The preference of users for online content, the demand of readers for a broader range of content, and the rising costs of library shelf space all contributed to bringing about this change. A variety of approaches has emerged to support access to these digital journals. The common ones require libraries to access content through publishers, which invariably means libraries lose long-term control of the journals to which they have subscribed. As an alternative, the Lots of Copies Keep Stuff Safe (LOCKSS) approach enables libraries to regain custody of journal assets while maintaining the access and licence terms stipulated by the publisher. This article describes the UK LOCKSS Pilot Programme; a two-year JISC/CURL (Joint Information Systems Committee/Consortium of Research Libraries in the British Isles)-funded initiative to explore issues associated with the practical implementation of LOCKSS in the UK Higher Education institutions. It examines the pilot from the perspective of the LOCKSS Technical Support Service, a core component of the Pilot Programme

Using Timed-Release Cryptography to Mitigate Preservation Risk of Embargo Periods

This research defines Time-Locked Embargo, a framework designed to mitigate the Preservation Risk Interval: the preservation risk associated with embargoed scholarly material. Due to temporary access restrictions, embargoed data cannot be distributed freely and thus preserved via data refreshing during the embargo time interval. A solution to mitigate the risk of data loss has been developed by suggesting a data dissemination framework that allows data refreshing of encrypted instances of embargoed content in an open, unrestricted scholarly community. This framework has been developed by exploiting implementations of existing technologies to time-lock data using Timed-Release Cryptology (TRC) so that it can be deployed s digital resources encoded in the MPEG-21 Digital Item Description Language (DIDL) complex object format to harvesters interested in harvesting a local copy of content by utilizing The Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH), a widely accepted interoperability standard for the exchange of metadata. The framework successfully demonstrates dynamic record identification, time-lock puzzle (TLP) encryption, encapsulation and dissemination as XML documents. This thesis dissertation presents the framework architecture and provides a quantitative analysis of an implementation. The framework demonstrates successful data harvest of time-locked embargoed data with minimum time overhead without compromising data security and integrity

Preserving Peer Replicas By Rate-Limited Sampled Voting in LOCKSS

The LOCKSS project has developed and deployed in a world-wide test a peer-to-peer system for preserving access to journals and other archival information published on the Web. It consists of a large number of independent, low-cost, persistent web caches that cooperate to detect and repair damage to their content by voting in "opinion polls." Based on this experience, we present a design for and simulations of a novel protocol for voting in systems of this kind. It incorporates rate limitation and intrusion detection to ensure that even some very powerful adversaries attacking over many years have only a small probability of causing irrecoverable damage before being detected.