06371 Abstracts Collection -- From Security to Dependability

From 10.09.06 to 15.09.06, the Dagstuhl Seminar 06371 ``From Security to Dependability\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

LIPIcs

Fault-tolerant distributed algorithms play an important role in many critical/high-availability applications. These algorithms are notoriously difficult to implement correctly, due to asynchronous communication and the occurrence of faults, such as the network dropping messages or computers crashing. Nonetheless there is surprisingly little language and verification support to build distributed systems based on fault-tolerant algorithms. In this paper, we present some of the challenges that a designer has to overcome to implement a fault-tolerant distributed system. Then we review different models that have been proposed to reason about distributed algorithms and sketch how such a model can form the basis for a domain-specific programming language. Adopting a high-level programming model can simplify the programmer's life and make the code amenable to automated verification, while still compiling to efficiently executable code. We conclude by summarizing the current status of an ongoing language design and implementation project that is based on this idea

Hybris: Robust Hybrid Cloud Storage

International audienceBesides well-known benefits, commodity cloud storage also raises concerns that include security, reliability, and consistency. We present Hybris key-value store, the first robust hybrid cloud storage system, aiming at addressing these concerns leveraging both private and public cloud resources. Hybris robustly replicates metadata on trusted private premises (private cloud), separately from data which is dispersed (using replication or erasure coding) across multiple untrusted public clouds. Hybris maintains metadata stored on private premises at the order of few dozens of bytes per key, avoiding the scalability bottleneck at the private cloud. In turn, the hybrid design allows Hybris to efficiently and robustly tolerate cloud outages, but also potential malice in clouds without overhead. Namely, to tolerate up to f malicious clouds, in the common case of the Hybris variant with data replication, writes replicate data across f + 1 clouds, whereas reads involve a single cloud. In the worst case, only up to f additional clouds are used. This is considerably better than earlier multi-cloud storage systems that required costly 3f + 1 clouds to mask f potentially malicious clouds. Finally, Hybris leverages strong metadata consistency to guarantee to Hybris applications strong data consistency without any modifications to the eventually consistent public clouds. We implemented Hybris in Java and evaluated it using a series of micro and macro-benchmarks. Our results show that Hybris significantly outperforms comparable multi-cloud storage systems and approaches the performance of bare-bone commodity public cloud storage

The Standing Stones of Medieval Bosnia: Heresy, Dualism and Symbols in Pre-Ottoman Balkans

The aim of this dissertation is to interpret the enigmatic imagery of the steak, the roughly 60,000 monumental, monolithic standing stones found on the territories of modern-day Bosnia and Herzegovina and its neighbouring regions. Around 30% of the stones are adorned with low reliefs depicting a variety of symbols such as crosses, crescents, rings and rosettes, as well as more complex figural compositions involving orants, circle dances and stag hunts. The rare and terse inscriptions found on the stones allow us to date their production between the 13th and 15th centuries and to link their creation to the medieval Bosnian state and its indigenous religious organization known as the Bosnian Church. My thesis is that the Bosnian Church adhered to what is known as a moderately dualistic theology. In order to justify this interpretation, I firstly analyze the terms heresy and dualism in their historical context(s). Secondly, I provide a re-reading of the primary documents linked to the Bosnian Church, arguing that it was related to other medieval dualist movements such as the Paulicians of eastern Anatolia, the Bogomils of Bulgaria and the Patarens/Cathars of Western Europe. Finally, I interpret the steak imagery in accordance with this view, demonstrating that it can be understood as a symbolic language with several layers of meaning. The dissertation encompasses historical, theological, iconographic and anthropological questions, shedding new light on the nature of medieval heresy/dualist Christianity, the history of medieval Bosnia, and the symbolism of a neglected aspect of European material culture

Imagining Demons in Post-Byzantine Jerusalem: John of Damascus and the Consolidation of Classical Christian Demonology

This dissertation traces the consolidation of a classical Christian framework for demonology in the theological corpus of John of Damascus (c. 675 – c. 750), an eighth century Greek theologian writing in Jerusalem. When the Damascene sat down to write, I argue, there was a great variety of demonological options available to him, both in the depth of the Christian tradition, and in the ambient local imagination. John’s genius lies first in what he chose not to include, but second in his ability to synthesize a minimalistic demonology out of a complex body of material and integrate it into a broader theological system. John’s synthesis was so effective, in fact, that it looks reflexively obvious as a statement of Christian demonology in the Scriptural-patristic tradition: it would not necessarily have been so to his contemporaries.I begin the study with an invitation to enter into an imaginative of reading John through the epithet “destroyer of demons” attached to him in his commemoration, and conclude it with an analysis of John’s understanding of the demonic as a “demon destroying” demonology. Between these terminal points are four chapters: two parsing what John drew from the Christian faith as he knew and had received it, and two considering extrinsic factors shaping John’s thought and imagination, including a discussion of alternate systems of demonology that we can locate in John’s approximate context. The final analysis mirrors my initial discussion of the themes that John inherited, drawing attention to the subtle ways he transformed his theological tradition in laying out a precise paradigm for future theological reflection on the nature of the devil and demons.John’s demonology – though minimal – is robust, and to read John using his ideas about the devil and demons as a focal point both draws attention to the complexities hidden within demonology as a subject and heightens our appreciation for the extraordinary qualities of the Damascene’s intellect and contribution. In broadest application, finally, recognizing the vast difference between the assumptions, methods, and means underwriting John’s demonology and our own in seeking to understand it prompts reflection on the nature and limits of the historical imagination in theology

Cities as Palimpsests?

The metaphor of the palimpsest has been increasingly invoked to conceptualize cities with deep, living pasts. This volume seeks to think through, and beyond, the logic of the palimpsest, asking whether this fashionable trope slyly forces us to see contradiction where local inhabitants saw (and see) none, to impose distinctions that satisfy our own assumptions about historical periodization and cultural practice, but which bear little relation to the experience of ancient, medieval or early modern persons. Spanning the period from Constantine’s foundation of a New Rome in the fourth century to the contemporary aftermath of the Lebanese civil war, this book integrates perspectives from scholars typically separated by the disciplinary boundaries of late antique, Islamic, medieval, Byzantine, Ottoman and modern Middle Eastern studies, but whose work is united by their study of a region characterized by resilience rather than rupture. The volume includes an introduction and eighteen contributions from historians, archaeologists and art historians who explore the historical and cultural complexity of eastern Mediterranean cities. The authors highlight the effects of the multiple antiquities imagined and experienced by persons and groups who for generations made these cities home, and also by travelers and other observers who passed through them. The independent case studies are bound together by a shared concern to understand the many ways in which the cities’ pasts live on in their presents

The Role of Non-Human Creation in the Liturgical Feasts of the Eastern Orthodox Tradition: Towards an Orthodox Ecological Theology

This thesis examines the role played by non-human creation in the liturgies for the feast of Holy Pascha (Easter), of the twelve major feasts of the Orthodox Church, and of the period of Great Lent. Applying to liturgical texts and practices the methodology developed by Paul Ricoeur for biblical interpretation, the thesis argues that the kind of world opened by these liturgies allows for the participation of non-human creatures in the liturgy and thus is amenable to an ecological theology. It investigates the implications of the liturgical texts for contemporary theological reflection about salvation, incarnation, sin, and theosis in light of the ecological crisis and the frequent Orthodox claim that the liturgy is ‘cosmic’ in scope. Chapter 1 looks at the role of non-human creation in the Paschal/Pentecost season and lays out the case for the need to include all of creation. Chapter 2 focuses on the feasts of the incarnation and argues for a more inclusive theological interpretation of the incarnation. Chapter 3 examines the liturgies of Lent and Holy Week and develops hamartiological implications of the ecological crisis. The final chapter focuses on the feasts of Theophany and the Transfiguration and proposes a view of theosis that extends beyond humans

Cities as Palimpsests?

The metaphor of the palimpsest has been increasingly invoked to conceptualize cities with deep, living pasts. This volume seeks to think through, and beyond, the logic of the palimpsest, asking whether this fashionable trope slyly forces us to see contradiction where local inhabitants saw (and see) none, to impose distinctions that satisfy our own assumptions about historical periodization and cultural practice, but which bear little relation to the experience of ancient, medieval or early modern persons. Spanning the period from Constantine’s foundation of a New Rome in the fourth century to the contemporary aftermath of the Lebanese civil war, this book integrates perspectives from scholars typically separated by the disciplinary boundaries of late antique, Islamic, medieval, Byzantine, Ottoman and modern Middle Eastern studies, but whose work is united by their study of a region characterized by resilience rather than rupture. The volume includes an introduction and eighteen contributions from historians, archaeologists and art historians who explore the historical and cultural complexity of eastern Mediterranean cities. The authors highlight the effects of the multiple antiquities imagined and experienced by persons and groups who for generations made these cities home, and also by travelers and other observers who passed through them. The independent case studies are bound together by a shared concern to understand the many ways in which the cities’ pasts live on in their presents