10292 Abstracts Collection and Summary -- Resilience Assessment and Evaluation

From July 18 to July 23, 2010 the Dagstuhl Seminar 10292 ``Resilience Assessment and Evaluation \u27\u27 was held in Schloss Dagstuhl~--~Leibniz Center for Informatics. 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

Aging and Rejuvenation Models of Load Changing Attacks in Micro-Grids

Recent cyber-attacks in critical infrastructures have highlighted the importance of investigating how to improve Smart-Grids (SG) resiliency. In the future, it is envisioned that grid connected micro-grids would have the ability of operating in 'islanded mode’ in the event of a grid-level failure. In this work, we propose a method for unfolding aging and rejuvenation models into their sequential counterparts to enable the computation of transient state probabilities in the proposed models. We have applied our methodology to one specific security attack scenario and four large campus micro-grids case studies. We have shown how to convert the software aging and rejuvenation, with cycles, to its unfolded counterpart. We then used the unfolded counterpart to support the survivability computation. We were able to analytically evaluate the transient failure probability and the associated Instantaneous Expected Energy Not Supplied metric, for each of the four case studies, from one specific attack. We envision several practical applications of the proposed methodology. First, because the micro-grid model is solved analytically, the approach can be used to support micro-grid engineering optimizations accounting for security intrusions. Second, micro-grid engineers could use the approach to detect security attacks by monitoring for unexpected deviations of the Energy Not Supplied metric

Scalability Assessment of Microservice Architecture Deployment Configurations: A Domain-based Approach Leveraging Operational Profiles and Load Tests

Abstract Microservices have emerged as an architectural style for developing distributed applications. Assessing the performance of architecture deployment configurations — e.g., with respect to deployment alternatives — is challenging and must be aligned with the system usage in the production environment. In this paper, we introduce an approach for using operational profiles to generate load tests to automatically assess scalability pass/fail criteria of microservice configuration alternatives. The approach provides a Domain-based metric for each alternative that can, for instance, be applied to make informed decisions about the selection of alternatives and to conduct production monitoring regarding performance-related system properties, e.g., anomaly detection. We have evaluated our approach using extensive experiments in a large bare metal host environment and a virtualized environment. First, the data presented in this paper supports the need to carefully evaluate the impact of increasing the level of computing resources on performance. Specifically, for the experiments presented in this paper, we observed that the evaluated Domain-based metric is a non-increasing function of the number of CPU resources for one of the environments under study. In a subsequent series of experiments, we investigate the application of the approach to assess the impact of security attacks on the performance of architecture deployment configurations

Unravelling Ariadne’s Thread: Exploring the Threats of Decentralised DNS

The current landscape of the core Internet technologies shows considerable centralisation with the big tech companies controlling the vast majority of traffic and services. This situation has sparked a wide range of decentralisation initiatives with blockchain technology being among the most prominent and successful innovations. At the same time, over the past years there have been considerable attempts to address the security and privacy issues affecting the Domain Name System (DNS). To this end, it is claimed that Blockchain-based DNS may solve many of the limitations of traditional DNS. However, such an alternative comes with its own security concerns and issues, as any introduction and adoption of a new technology typically does - let alone a disruptive one. In this work we present the emerging threat landscape of blockchain-based DNS and we empirically validate the threats with real-world data. Specifically, we explore a part of the blockchain DNS ecosystem in terms of the browser extensions using such technologies, the chain itself (Namecoin and Emercoin), the domains, and users who have been registered in these platforms. Our findings reveal several potential domain extortion attempts and possible phishing schemes. Finally, we suggest countermeasures to address the identified threats, and we identify emerging research themes

Rejuvenation and the Spread of Epidemics in General Topologies

International audienceEpidemic models have received significant atten-tion in the past few decades to study the propagation of viruses, worms and ideas in computer and social networks. In the case of viruses, the goal is to understand how the topology of the network and the properties of the nodes that comprise the network, together, impact the spread of the epidemics. In this paper, we propose rejuvenation as a way to cope with epidemics. Then, we present a model to study the effect of rejuvenation and of the topology on the steady-state number of infected and failed nodes. We distinguish between a state in which the virus is incubating and in which symptoms might not be visible and yet they may be contagious and infecting other nodes, and a state of failure where symptoms are clear. Sampling costs might be incurred to examine nodes in search for viruses at an early stage. Using the proposed model, we show that the sampling rate admits at most one local minimum greater than zero. Then, we numerically illustrate the impact of different system parameters on the optimal sampling rate, indicating when rejuvenation is more beneficial