1st Kassel Student Workshop on Security in Distributed Systems

With this document, we provide a compilation of in-depth discussions on some of the most current security issues in distributed systems. The six contributions have been collected and presented at the 1st Kassel Student Workshop on Security in Distributed Systems (KaSWoSDS’08). We are pleased to present a collection of papers not only shedding light on the theoretical aspects of their topics, but also being accompanied with elaborate practical examples. In Chapter 1, Stephan Opfer discusses Viruses, one of the oldest threats to system security. For years there has been an arms race between virus producers and anti-virus software providers, with no end in sight. Stefan Triller demonstrates how malicious code can be injected in a target process using a buffer overflow in Chapter 2. Websites usually store their data and user information in data bases. Like buffer overflows, the possibilities of performing SQL injection attacks targeting such data bases are left open by unwary programmers. Stephan Scheuermann gives us a deeper insight into the mechanisms behind such attacks in Chapter 3. Cross-site scripting (XSS) is a method to insert malicious code into websites viewed by other users. Michael Blumenstein explains this issue in Chapter 4. Code can be injected in other websites via XSS attacks in order to spy out data of internet users, spoofing subsumes all methods that directly involve taking on a false identity. In Chapter 5, Till Amma shows us different ways how this can be done and how it is prevented. Last but not least, cryptographic methods are used to encode confidential data in a way that even if it got in the wrong hands, the culprits cannot decode it. Over the centuries, many different ciphers have been developed, applied, and finally broken. Ilhan Glogic sketches this history in Chapter 6.

Economics of Hybrid Photovoltaic Power Plants

The global power supply stability is faced to several severe and fundamental threats, in particular steadily increasing power demand, diminishing and degrading fossil and nuclear energy resources, very harmful greenhouse gas emissions, significant energy injustice and a structurally misbalanced ecological footprint. Photovoltaic (PV) power systems are analysed in various aspects focusing on economic and technical considerations of supplemental and substitutional power supply to the constraint conventional power system. To infer the most relevant system approach for PV power plants several solar resources available for PV systems are compared. By combining the different solar resources and respective economics, two major PV systems are identified to be very competitive in almost all regions in the world. The experience curve concept is used as a key technique for the development of scenario assumptions on economic projections for the decade of the 2010s. Main drivers for cost reductions in PV systems are learning and production growth rate, thus several relevant aspects are discussed such as research and development investments, technical PV market potential, different PV technologies and the energetic sustainability of PV. Three major market segments for PV systems are identified: off-grid PV solutions, decentralised small scale on-grid PV systems (several kWp) and large scale PV power plants (tens of MWp). Mainly by application of ‘grid-parity’ and ‘fuel-parity’ concepts per country, local market and conventional power plant basis, the global economic market potential for all major PV system segments is derived. PV power plant hybridization potential of all relevant power technologies and the global power plant structure are analyzed regarding technical, economical and geographical feasibility. Key success criteria for hybrid PV power plants are discussed and comprehensively analysed for all adequate power plant technologies, i.e. oil, gas and coal fired power plants, wind power, solar thermal power (STEG) and hydro power plants. For the 2010s, detailed global demand curves are derived for hybrid PV-Fossil power plants on a per power plant, per country and per fuel type basis. The fundamental technical and economic potentials for hybrid PV-STEG, hybrid PV-Wind and hybrid PV-Hydro power plants are considered. The global resource availability for PV and wind power plants is excellent, thus knowing the competitive or complementary characteristic of hybrid PV-Wind power plants on a local basis is identified as being of utmost relevance. The complementarity of hybrid PV-Wind power plants is confirmed. As a result of that almost no reduction of the global economic PV market potential need to be expected and more complex power system designs on basis of hybrid PV-Wind power plants are feasible. The final target of implementing renewable power technologies into the global power system is a nearly 100% renewable power supply. Besides balancing facilities, storage options are needed, in particular for seasonal power storage. Renewable power methane (RPM) offers respective options. A comprehensive global and local analysis is performed for analysing a hybrid PV-Wind-RPM combined cycle gas turbine power system. Such a power system design might be competitive and could offer solutions for nearly all current energy system constraints including the heating and transportation sector and even the chemical industry. Summing up, hybrid PV power plants become very attractive and PV power systems will very likely evolve together with wind power to the major and final source of energy for mankind.

Climate-Adaptive Community Water Management for Food Security: Experiences from the UNDP Community Water Initiative

Facing the double menace of climate change threats and water crisis, poor communities have now encountered ever more severe challenges in ensuring agricultural productivity and food security. Communities hence have to manage these challenges by adopting a comprehensive approach that not only enhances water resource management, but also adapts agricultural activities to climate variability. Implemented by the Global Environment Facility’s Small Grants Programme, the Community Water Initiative (CWI) has adopted a distinctive approach to support demand-driven, innovative, low cost and community-based water resource management for food security. Experiences from CWI showed that a comprehensive, locally adapted approach that integrates water resources management, poverty reduction, climate adaptation and community empowerment provides a good model for sustainable development in poor rural areas.

Wild food trees in Eastern Nuba Mountains, Sudan: Use diversity and threatening factors

This study was conducted in 2010 in Eastern Nuba Mountains, Sudan to investigate ethnobotanical food and non-food uses of 16 wild edible fruit producing trees. Quantitative and qualitative information was collected from 105 individuals distributed in 7 villages using a semi-structured questionnaire. Also gathering of data was done using a number of rapid rural appraisal techniques, including key informant interviews, group discussion, secondary data sources and direct observations. Data was analysed using fidelity level and informant consensus factor methods to reveal the cultural importance of species and use category. Utilizations for timber products were found of most community importance than food usages, especially during cultivated food abundance. Balanites aegyptiaca, Ziziphus spina-christi and Tamarindus indica fruits were asserted as most preferable over the others and of high marketability in most of the study sites. Harvesting for timber-based utilizations in addition to agricultural expansion and overgrazing were the principal threats to wild edible food producing trees in the area. The on and off prevailing armed conflict in the area make it crucial to conserve wild food trees which usually play a more significant role in securing food supply during emergency times, especially in times of famine and wars. Increasing the awareness of population on importance of wild food trees and securing alternative income sources, other than wood products, is necessary in any rural development programme aiming at securing food and sustaining its resources in the area.

Farmers’ perspectives with regard to arable crop production and deagrarianisation: an analysis of Nkonkobe Municipality, South Africa

This exploratory study evaluated biophysical, cultural and socio-economic factors affecting crop production and land utilisation in the Nkonkobe Municipality, South Africa. The study sought to establish what farmers in the area perceive as serious threats to crop production, drivers for land abandonment, and how best current agricultural production could be intensified. The farmers’ perspectives were assessed through interviews using semi-structured and open-ended questionnaires. The results of the study revealed declining crop productivity and increase in land abandonment in the Municipality. The biophysical drivers of land abandonment were low and erratic rainfall and land degradation while the socio-economic drivers were labour shortages due to old age and youth movement to cities, lack of farming equipment and security concerns. The most abandoned crops were maize, sorghum and wheat. This trend was attributed to the labour intensiveness of cereal production and a shift in dietary preference to purchased rice. These findings should be factored in any programmes that seek to increase land utilisation and crop productivity in the Municipality.

Human and Raptor Interactions in the Context of a Nomadic Society

This research project focuses on contemporary eagle-taming falconry practice of the Altaic Kazakhs animal herding society in Bayan Ulgii Province in Western Mongolia. It aims to contributing both theoretical and empirical criteria for cultural preservation of Asian falconry. This cultural as well as environmental discourse is illustrated with concentrated field research framed by ecological anthropology and ethno-ornithology from the viewpoint of “Human-Animal Interaction (HAI)” and “Human-Animal Behavior (HAB)”. Part I (Chapter 2 & 3) explores ethno-archaeological and ethno-ornithological dimensions by interpretive research of archaeological artefacts which trace the historical depth of Asian falconry culture. Part II (Chapter 4 & 5) provides an extensive ethnographic narrative of Altaic Kazakh falconry, which is the central part of this research project. The “Traditional Art and Knowledge (TAK)” in human-raptor interactions, comprising the entire cycle of capture, perch, feeding, training, hunting, and release, is presented with specific emphasis on its relation to environmental and societal context. Traditional falconry as integral part of a nomadic lifestyle has to face some critical problems nowadays which necessitate preventing the complete disappearance of this outstanding indigenous cultural heritage. Part III (Chapter 6 & 7) thus focuses on the cultural sustainability of Altaic Kazakh falconry. Changing livelihoods, sedentarisation, and decontextualisation are identified as major threats. The role of Golden Eagle Festivals is critically analysed with regard to positive and negative impact. This part also intends to contribute to the academic definition of eagle falconry as an intangible cultural heritage, and to provide scientific criteria for a preservation master plan, as well as stipulate local resilience by pointing to successive actions needed for conservation. This research project concludes that cultural sustainability of Altaic Kazakh falconry needs to be supported from the angles of three theoretical frameworks; (1) Cultural affairs for protection based on the concept of nature-guardianship in its cultural domain, (2) Sustainable development and improvement of animal herding productivity and herder’s livelihood, (3) Natural resource management, especially supporting the population of Golden Eagles, their potential prey animals, and their nesting environment.