Bi-objective Optimization of Satellite Payload Power Configuration

in International Conference on Metaheuristics and Nature Inspired Computing (META 2014) (2014, October)

Exploiting the Hard-wired Vulnerabilities of Newscast via Connectivity-splitting Attack

in Proc. of the IEEE Intl. Conf. on Network and System Security (NSS 2014) (2014, October)

Newscast is a model for information dissemination and mem- bership management in large-scale, agent-based distributed systems. It deploys a simple, peer-to-peer data exchange protocol. The Newscast pro ... [more ▼]

Newscast is a model for information dissemination and mem- bership management in large-scale, agent-based distributed systems. It deploys a simple, peer-to-peer data exchange protocol. The Newscast pro- tocol forms an overlay network and keeps it connected by means of an epidemic algorithm, thus featuring a complex, spatially structured, and dynamically changing environment. It has recently become very popu- lar due to its inherent resilience to node volatility as it exhibits strong self-healing properties. In this paper, we analyze the robustness of the Newscast model when executed in a distributed environment subjected to malicious acts. More precisely, we evaluate the resilience of Newscast against cheating faults and demonstrate that even a few naive cheaters are able to defeat the protocol by breaking the network connectivity. Concrete experiments are performed using a framework that implements both the protocol and the cheating model considered in this work. [less ▲]

Analysis of the Data Flow in the Newscast Protocol for Possible Vulnerabilities

in Proc. of Intl. Conf. on Cryptography and Security System (CSS'14) (2014, September)

Management of an Academic HPC Cluster: The UL Experience

in Proc. of the 2014 Intl. Conf. on High Performance Computing Simulation (HPCS 2014) (2014, July)

The intensive growth of processing power, data storage and transmission capabilities has revolutionized many aspects of science. These resources are essential to achieve high-quality results in many ... [more ▼]

The intensive growth of processing power, data storage and transmission capabilities has revolutionized many aspects of science. These resources are essential to achieve high-quality results in many application areas. In this context, the University of Luxembourg (UL) operates since 2007 an High Performance Computing (HPC) facility and the related storage. The aspect of bridging computing and storage is a requirement of UL service – the reasons are both legal (certain data may not move) and performance related. Nowa- days, people from the three faculties and/or the two Interdisciplinary centers within the UL, are users of this facility. More specifically, key research priorities such as Systems Bio-medicine (by LCSB) and Security, Reliability & Trust (by SnT) require access to such HPC facilities in order to function in an adequate environment. The management of HPC solutions is a complex enterprise and a constant area for discussion and improvement. The UL HPC facility and the derived deployed services is a complex computing system to manage by its scale: at the moment of writing, it consists of 150 servers, 368 nodes (3880 computing cores) and 1996 TB of shared raw storage which are all configured, monitored and operated by three per- sons using advanced IT automation solutions based on Puppet [1], FAI [2] and Capistrano [3]. This paper covers all the aspects in relation to the management of such a complex infrastructure, whether technical or administrative. Most design choices or implemented approaches have been motivated by several years of experience in addressing research needs, mainly in the HPC area but also in complementary services (typically Web-based). In this context, we tried to answer in a flexible and convenient way many technological issues. This experience report may be of interest for other research centers belonging either to the public or the private sector looking for good if not best practices in cluster architecture and management. [less ▲]

Comparison of Multi-objective Optimization Algorithms for the JShadObf JavaScript Obfuscator

in Proc. of the 17th Intl. Workshop on Nature Inspired Distributed Computing (NIDISC 2014), part of the 28th IEEE/ACM Intl. Parallel and Distributed Processing Symposium (IPDPS 2014) (2014, May)

With the advent of the Cloud Computing (CC) paradigm and the explosion of new Web Services proposed over the Internet (such as Google Office Apps, Dropbox or Doodle), the protection of the programs at the ... [more ▼]

With the advent of the Cloud Computing (CC) paradigm and the explosion of new Web Services proposed over the Internet (such as Google Office Apps, Dropbox or Doodle), the protection of the programs at the heart of these services becomes more and more crucial, especially for the companies making business on top of these services. The majority of these services are now using the JavaScript programming language to interact with the user as all modern web browsers – either on desktops, game consoles, tablets or smart phones – include JavaScript interpreters making it the most ubiquitous programming language in history. This context renew the interest of obfuscation techniques, i.e. to render a program "unintelligible" without altering its functionality. The objective is to prevent the reverse-engineering on the program for a certain period of time – an absolute protection by this way being unrealistic since stand-alone obfuscation for arbitrary programs has been proven impossible in 2001. In [11], we have presented JSHADOBF, an obfuscation framework based on evolutionary heuristics designed to optimize for a given input JavaScript program, the sequence of transformations that should be applied to the source code to improve its obfuscation capacity. Measuring this capacity is based on the combination of several metrics optimized simultaneously with Multi-Objective Evolutionary Algorithms (MOEAs). In this paper, we extend and complete the experiments made around JSHADOBF to ana- lyze the impact of the underlying Multi-Objective Evolutionary Algorithms (MOEAs) algorithm onto the obfuscation process. In particular, we compare the performances of NSGA-II and MOEAD (two reference algorithms in the optimization domain) on top of JSHADOBF to first obfuscate a pedagogical program inherited from linear algebra, then one of the most popular and widely used JavaScript library: JQuery. [less ▲]

Hybridisation Schemes for Communication Satellite Payload Configuration Optimisation

in 17th European Conference on Applications of Evolutionary Computation (EvoApplications 2014) (2014, April)

Evaluating the HPC Performance and Energy-Efficiency of Intel and ARM-based systems with synthetic and bioinformatics workloads

Report (2014)

The increasing demand for High Performance Computing (HPC) paired with the higher power requirements of the ever-faster systems has led to the search for both performant and more energy-efficient ... [more ▼]

The increasing demand for High Performance Computing (HPC) paired with the higher power requirements of the ever-faster systems has led to the search for both performant and more energy-efficient architectures. This article compares and contrasts the performance and energy efficiency of two modern, traditional Intel Xeon and low power ARM-based clusters, which are tested with the recently developed High Performance Conjugate Gradient (HPCG) benchmark and the ABySS, FASTA and MrBayes bioinformatics applications. We show a higher Performance per Watt valuation of the ARM cluster, and lower energy usage during the tests, which does not offset the much faster job completion rate obtained by the Intel cluster, making the latter more suitable for the considered workloads given the disparity in the performance results. [less ▲]

Adaptive Energy Efficient Distributed VoIP Load Balancing in Federated Cloud Infrastructure

in IEEE International Conference on Cloud Networking (CLOUDNET), Luxembourg City, 2014. (2014)

Evolutionary Algorithms for Mobile Ad Hoc Networks

Book published by John Wiley & Sons (2014)

Energy Savings on a Cloud-based Opportunistic Infrastructure

in Service Oriented Computing ICSOC 2013 Workshops (2014)

In this paper, we address energy savings on a Cloud-based opportunistic infrastructure. The infrastructure implements opportunis- tic design concepts to provide basic services, such as virtual CPUs, RAM ... [more ▼]

In this paper, we address energy savings on a Cloud-based opportunistic infrastructure. The infrastructure implements opportunis- tic design concepts to provide basic services, such as virtual CPUs, RAM and Disk while profiting from unused capabilities of desktop computer laboratories in a non-intrusive way. We consider the problem of virtual machines consolidation on the oppor- tunistic cloud computing resources. We investigate four workload packing algorithms that place a set of virtual machines on the least number of physical machines to increase resource utilization and to transition parts of the unused resources into a lower power states or switching off. We em- pirically evaluate these heuristics on real workload traces collected from our experimental opportunistic cloud, called UnaCloud. The final aim is to implement the best strategy on UnaCoud. The results show that a consolidation algorithm implementing a policy taking into account fea- tures and constraints of the opportunistic cloud saves energy more than 40% than related consolidation heuristics, over the percentage earned by the opportunistic environment. [less ▲]