Enhancing intrusion resilience in publicly accessible distributed systems

PhD ThesisThe internet is increasingly used as a means of communication by many businesses. Online shopping has become an important commercial activity and many governmental bodies offer services online. Malicious intrusion into these systems can have major negative consequences, both for the providers and users of these services. The need to protect against malicious intrusion, coupled with the difficulty of identifying and removing all possible vulnerabilities in a distributed system, have led to the use of systems that can tolerate intrusions with no loss of integrity. These systems require that services be replicated as deterministic state machines, a relatively hard task in practice, and do not ensure that confidentiality is maintained when one or more replicas are successfully intruded into. This thesis presents FORTRESS, a novel intrusion-resilient system that makes use of proactive obfuscation techniques and cheap off-the-shelf hardware to enhance intrusionresilience. FORTRESS uses proxies to prevent clients accessing servers directly, and regular replacement of proxies and servers with differently obfuscated versions. This maintains both confidentiality and integrity as long as an attacker does not compromise the system as a whole. The expected lifetime until system compromise of the FORTRESS system is compared to those of state machine replicated and primary backup systems when confronted with an attacker capable of launching distributed attacks against known vulnerabilities. Thus, FORTRESS is demonstrated to be a viable alternative to building intrusion-tolerant systems using deterministic state machine replication. The performance overhead of the FORTRESS system is also evaluated, using both a general state transfer framework for distributed systems, and a lightweight framework for large scale web applications. This shows the FORTRESS system has a sufficiently small performance overhead to be of practical use

Static analysis for facilitating secure and reliable software

Software security and reliability are aspects of major concern for software development enterprises that wish to deliver dependable software to their customers. Several static analysis-based approaches for facilitating the development of secure and reliable software have been proposed over the years. The purpose of the present thesis is to investigate these approaches and to extend their state of the art by addressing existing open issues that have not been sufficiently addressed yet. To this end, an empirical study was initially conducted with the purpose to investigate the ability of software metrics (e.g., complexity metrics) to discriminate between different types of vulnerabilities, and to examine whether potential interdependencies exist between different vulnerability types. The results of the analysis revealed that software metrics can be used only as weak indicators of specific security issues, while important interdependencies may exist between different types of vulnerabilities. The study also verified the capacity of software metrics (including previously uninvestigated metrics) to indicate the existence of vulnerabilities in general. Subsequently, a hierarchical security assessment model able to quantify the internal security level of software products, based on static analysis alerts and software metrics is proposed. The model is practical, since it is fully-automated and operationalized in the form of individual tools, while it is also sufficiently reliable since it was built based on data and well-accepted sources of information. An extensive evaluation of the model on a large volume of empirical data revealed that it is able to reliably assess software security both at product- and at class-level of granularity, with sufficient discretion power, while it may be also used for vulnerability prediction. The experimental results also provide further support regarding the ability of static analysis alerts and software metrics to indicate the existence of software vulnerabilities. Finally, a mathematical model for calculating the optimum checkpoint interval, i.e., the checkpoint interval that minimizes the execution time of software programs that adopt the application-level checkpoint and restart (ALCR) mechanism was proposed. The optimum checkpoint interval was found to depend on the failure rate of the application, the execution cost for establishing a checkpoint, and the execution cost for restarting a program after failure. Emphasis was given on programs with loops, while the results were illustrated through several numerical examples.Open Acces

Between panegyric and history: literary representations of the Emperor Valentinian I (364-375)

This thesis examines the literary representation of the Pannonian emperor Valentinian I (364–375) in two different types of source dated to the fourth and fifth centuries AD. More specifically, it analyses how literary sources which were contemporaneous with Valentinian’s reign (Symmachus’ imperial panegyrics; and imperial legislation) and which promoted the ‘official’ view of Valentinian’s regime, were received and interpreted in the later historical sources for the emperor’s reign (namely, Ammianus Marcellinus’ Res Gestae; and the histories of the Christian historians Tyrannius Rufinus, Paulus Orosius, Socrates Scholasticus, Sozomen and Theodoret). By analysing three themes (dynastic, military and religious) which were prominent in both forms of representation, this thesis explores how and why these ‘contemporary’ and ‘historical’ representations of the emperor differed, and asks what the interaction of these sources can tell us about the literary representation of Valentinian more generally

Between security, law enforcement and harm reduction: drug policing at commercial music festivals in England

In this thesis, I use an ethnographic methodology to explore the implementation of drug policing at commercial music festivals in England. I argue that festival drug policing is primarily concerned with the anticipation and mitigation of drug-related risk, and festivals adopt an array of security, enforcement and harm reduction approaches under the ‘3: Ps’ (Prevent, Pursue and Protect) in pursuit of this. With an lens on the in-situ decision making of policing, security and management actors on the ground, I illustrate how drug policies are negotiated between agencies, in order to satisfy their sometimes competing risk-perceptions and interests in their pursuit of drug security

London’s foundations protecting the geodiversity of the capital

This report describes a geodiversity audit of London commissioned by a partnership led by the Greater London Authority (GLA), which includes the British Geological Survey (BGS), Natural England, Government Office for London, London Biodiversity Partnership, London Borough of Lambeth, Harrow and Hillingdon Geological Society, South London London RIGS Groups, Hanson UK and Queen Mary College, University of London. The project was funded by an Aggregates Levy Sustainability Fund grant from Natural England plus additional support from the GLA, BGS and Natural England London Region. The audit began with a review of the available geodiversity documentation for London including: BGS field maps, databases and publications; Regional Important Geological Sites (RIGS) Group information; Natural England Sites of Special Scientific Interest (SSSI) and Geological Conservation Review (GCR) documentation; and documentation and data from the GLA and London Boroughs. An initial list of around 470 sites with potential for geodiversity value was compiled from this information. This list was then narrowed down to 100 for further assessment by exporting site locations to a GIS and cross-checking against digital aerial photography backed up by BGS staff local geological expertise. Using the procedure set out in this report field auditing was carried out by BGS staff and the South London RIGS Group between November 2007 and April 2008. From the list of 100 sites, 35 sites were found to be suitable for detailed auditing. Harrow and Hillingdon Geological Society audited a further site in November 2008, bringing the total to 36 sites. Using the criteria set out in this report 14 of the 36 sites are recommended for designation as Regionally Important Geological/geomorphological Sites (RIGS) in borough Local Development Documents. Of the 33 London boroughs, RIGS are recommended in eight, with five in Bromley, three in Croydon and one each in Lewisham, Ealing, Greenwich, Harrow, Hillingdon and Bexley. Using the criteria set out in this report 15 of the 36 sites have the potential to be designated as Locally Important Geological Sites (LIGS). These sites are located in nine boroughs, three in Waltham Forest, two in Bromley, two in Islington and one each in Barnet, Lewisham, Redbridge, Wandsworth, Southwark and Sutton. Planning proposals should have regard to geodiversity in order to implement strategic and local policies. Sites should be protected, managed and enhanced and, where ppropriate, new development should provide improvements to the geodiversity value of a site. This can include measures that promote public access, study, interpretation and appreciation of geodiversity. In addition to individual sites of geodiversity interest, Greater London has distinctive natural landscapes shaped by geological processes, such as undulating chalk downlands with dry valleys in south London, and river terraces forming long flat areas separated by steeper areas of terrace front slopes. This natural topographic geodiversity underlying London should be understood, respected and only altered in that knowledge with full knowledge of it origin and form. Planners are encouraged to use authentic contouring in restoration work and new landscaping schemes, maintain the contributions of natural topography, rock outcrops, landscape features, and to maintain soil quality, quantity and function

Space wars and the new urban imperialism

The dissertation analyzes recent urban transformations through the lens of space wars. The main focus is on investment flows in the commercial property market, changes in urban governance and changes in social geography, and how these three aspects are related. Drawing on cross border investment data, archive studies, interviews with key actors and street walking experiences in Copenhagen, Lisbon and New York, the book offers insight into the ?glocal? logic of urban imperialism and its tendency towards uneven development ? fundamental forces that shape our cities in the 21st century. In Chapter One, I introduce the concepts of space wars and the new urban imperialism and present the research questions and methodological considerations. Chapter Two analyzes processes of globalization in property markets through an empirical investigation into the commercial property market of Copenhagen. Globalization of property markets is defined, a framework for analysis is presented and methodological problems are reported. The chapter aims to improve our understanding of globalization in the sphere of immobile property, and to show to what extent globalization (in this limited sense) has occurred in Copenhagen. In Chapter Three I analyze linkages between rescaling of commercial property markets and changes in urban governance in Lisbon. The chapter aims to further advance understanding of globalization in the sphere of immobile property, and its relation with shifts in urban governance. Cautious comparisons with Copenhagen are made. Chapter Four expands the analysis of Copenhagen as a globalizing city. Through the optic of the imagineering of Copenhagen as ?creative city? ? part of Copenhagen's competition with other cities ? relations between globalization, urban governance and social geography are analyzed. The chapter problematizes what on the surface seems to be an unequivocally positive quality (?creative?) and goal (?creativity?). Chapter Five employs the concept of the global-local nexus of space wars, forging links between highly localized processes of urban transformation, competition between cities and global movements of capital and people. It shows how mental and material boundaries as well as ethnicity and class are central elements in space wars. Through the example of Sydhavn, a rapidly changing part of Copenhagen, the chapter aims to illustrate how processes of material and social construction and transformation of urban space constitute urban space wars, engaging actors at all scales. The Epilogue serves as a supplement to my short film ?Space wars: a street level odyssey through the centre of the American empire ? New York City?. The film offers a street level voyage through the urban topography of New York, centre of the American empire, showing how the rhythms of vagabond capitalism manifest themselves as space wars. At first glance, every day in the city seems an original performance, but underneath the surface, we find a myriad of rhythms that reveal traces of millennia of human cultures and histories. In urban centers throughout the globe we can observe contemporary modern society and the materialized topographies of different modes of time-space production. The film seeks to direct attention to, and stimulate discussion on issues of space wars at different scales and in different contexts

Towards climate resilience in agriculture for Southeast Asia: an overview for decision-makers.

This sourcebook, and accompanying poster learning series, is aimed at policy makers, planners in government, local research administrators, civil society partners and researchers in Southeast Asia. Compiled and repackaged by Dr. Julian Gonsalves and a resource team, the Climate-Smart Agriculture (CSA) source book draws from a rich pool of literature from over 700 sources. The compilation provides succinct, relevant and timely information about climate challenges, and potential solutions from previously published work in a simplified or a shortened form from around the world. While the focus is on challenges specific to Southeast Asia, solutions may come from, or already have been tested elsewhere; it is for this reason that articles from around the world have been included, to demonstrate that adaptation efforts are already being implemented, and a wide range of approaches and strategies are available. This resource seeks to bridge the gap between what policy makers know, and what research shows can work on the ground to improve adaptation, increase productivity, enhance livelihoods, and contribute to sustainable development affected by climate change. The related poster series can be found here: http://hdl.handle.net/10568/71099

Making sense of knowledge creation processes: The case of a Greek petrochemical industry.

This thesis is concerned with knowledge creation processes within service organizations, specifically in relation to the maintenance function. While bearing in mind the particular context of the study, the thesis argues that maintenance service work, when seen from such a knowledge creation perspective, affords important insights into the dynamic interrelations, links and social interactions within the knowledge creation processes themselves. To date, the knowledge management and organization studies literature tends not to treat these practical topics and theoretical issues in an integrated, holistic manner. The thesis addresses this lack using an in- depth, situated case study of the maintenance division of a major Greek petrochemical refinery. The research adopts an interpretative perspective and makes sense of knowledge creation processes through the theoretical lens of the Unified Model of Dynamic Knowledge Creation (Nonaka et al. 2001), combined with the knowledge activism framework (Von Krogh et al. 1997). Nonaka's framework, which guides data collection and analysis, suggests an approach to the investigation using the so-called SECI process. This process explains how knowledge creation unfolds, utilising the Japanese concept of Ba (which represents the process context), and the concept of knowledge assets (which corresponds to the process content). The explanation of important individual and group roles within knowledge creation processes using Von Krogh's framework integrates these concepts. This use of a process view of knowledge creation helps explain a wide variety of complex and situated interrelations that demonstrate the existence of different modes of knowledge creation. Thus, the approach to process inquiry along with the research design fertilize methodological discussions about research on knowledge creation processes. The core theoretical contribution of the research concerns the provision of a process view of knowledge creation. Other theoretical implications of the research findings relate to insights on the complex nature of the knowledge creation process within a work environment, extensions to the research framework, and recommendations for further conceptual developments. The research also contributes practical implications and insights into, and specific conclusions about, knowledge creation processes and how they might be effectively managed in service organizations more generally

Big Data Security (Volume 3)

After a short description of the key concepts of big data the book explores on the secrecy and security threats posed especially by cloud based data storage. It delivers conceptual frameworks and models along with case studies of recent technology