arXiv subjects

Samuel Kounev

Publications and source records attributed to Samuel Kounev.

25 records · Page 2Linked to original sources

arXiv2020

A Survey on Predictive Maintenance for Industry 4.0

Production issues at Volkswagen in 2016 lead to dramatic losses in sales of up to 400 million Euros per week. This example shows the huge financial impact of a working production facility for companies. Especially in the data-driven domains of Industry 4.0 and Industrial IoT with intelligent, connected machines, a conventional, static maintenance schedule seems to be old-fashioned. In this paper, we present a survey on the current state of the art in predictive maintenance for Industry 4.0. Based on a structured literate survey, we present a classification of predictive maintenance in the context of Industry 4.0 and discuss recent developments in this area.

cs.LG↗

arXiv2020

A Survey on Human Machine Interaction in Industry 4.0

Industry 4.0 or Industrial IoT both describe new paradigms for seamless interaction between humans and machines. Both concepts rely on intelligent, inter-connected cyber-physical production systems that are able to control the process flow of industrial production. As those machines take many decisions autonomously and further interact with production and manufacturing planning systems, the integration of human users requires new paradigms. In this paper, we provide an analysis of the current state-of-the-art in human-machine interaction in the Industry 4.0 domain.We focus on new paradigms that integrate the application of augmented and virtual reality technology. Based on our analysis, we further provide a discussion of research challenges.

cs.HC↗

arXiv2019

Hands Off my Database: Ransomware Detection in Databases through Dynamic Analysis of Query Sequences

Ransomware is an emerging threat which imposed a \$ 5 billion loss in 2017 and is predicted to hit \$ 11.5 billion in 2019. While initially targeting PC (client) platforms, ransomware recently made the leap to server-side databases - starting in January 2017 with the MongoDB Apocalypse attack, followed by other attack waves targeting a wide range of DB types such as MongoDB, MySQL, ElasticSearch, Cassandra, Hadoop, and CouchDB. While previous research has developed countermeasures against client-side ransomware (e.g., CryptoDrop and ShieldFS), the problem of server-side ransomware has received zero attention so far. In our work, we aim to bridge this gap and present DIMAQS (Dynamic Identification of Malicious Query Sequences), a novel anti-ransomware solution for databases. DIMAQS performs runtime monitoring of incoming queries and pattern matching using Colored Petri Nets (CPNs) for attack detection. Our system design exhibits several novel techniques to enable efficient detection of malicious query sequences globally (i.e., without limiting detection to distinct user connections). Our proof-of-concept implementation targets MySQL servers. The evaluation shows high efficiency with no false positives and no false negatives and very moderate performance overhead of under 5%. We will publish our data sets and implementation allowing the community to reproduce our tests and compare to our results.

cs.CR↗

arXiv2016

Ready for Rain? A View from SPEC Research on the Future of Cloud Metrics

In the past decade, cloud computing has emerged from a pursuit for a service-driven information and communication technology (ICT), into a signifcant fraction of the ICT market. Responding to the growth of the market, many alternative cloud services and their underlying systems are currently vying for the attention of cloud users and providers. Thus, benchmarking them is needed, to enable cloud users to make an informed choice, and to enable system DevOps to tune, design, and evaluate their systems. This requires focusing on old and new system properties, possibly leading to the re-design of classic benchmarking metrics, such as expressing performance as throughput and latency (response time), and the design of new, cloud-specififc metrics. Addressing this requirement, in this work we focus on four system properties: (i) elasticity of the cloud service, to accommodate large variations in the amount of service requested, (ii) performance isolation between the tenants of shared cloud systems, (iii) availability of cloud services and systems, and the (iv) operational risk of running a production system in a cloud environment.Focusing on key metrics, for each of these properties we review the state-of-the-art, then select or propose new metrics together with measurement approaches. We see the presented metrics as a foundation towards upcoming, industry-standard, cloud benchmarks. Keywords: Cloud Computing; Metrics; Measurement; Benchmarking; Elasticity; Isolation; Performance; Service Level Objective; Availability; Operational Risk.

cs.DC↗

arXiv2014

Technical Information on Vulnerabilities of Hypercall Handlers

Modern virtualized service infrastructures expose attack vectors that enable attacks of high severity, such as attacks targeting hypervisors. A malicious user of a guest VM (virtual machine) may execute an attack against the underlying hypervisor via hypercalls, which are software traps from a kernel of a fully or partially paravirtualized guest VM to the hypervisor. The exploitation of a vulnerability of a hypercall handler may have severe consequences such as altering hypervisor's memory, which may result in the execution of malicious code with hypervisor privilege. Despite the importance of vulnerabilities of hypercall handlers, there is not much publicly available information on them. This significantly hinders advances towards securing hypercall interfaces. In this work, we provide in-depth technical information on publicly disclosed vulnerabilities of hypercall handlers. Our vulnerability analysis is based on reverse engineering the released patches fixing the considered vulnerabilities. For each analyzed vulnerability, we provide background information essential for understanding the vulnerability, and information on the vulnerable hypercall handler and the error causing the vulnerability. We also show how the vulnerability can be triggered and discuss the state of the targeted hypervisor after the vulnerability has been triggered.

cs.CR↗

arXiv2014

Cloud Usage Patterns: A Formalism for Description of Cloud Usage Scenarios

Cloud computing is becoming an increasingly lucrative branch of the existing information and communication technologies (ICT). Enabling a debate about cloud usage scenarios can help with attracting new customers, sharing best-practices, and designing new cloud services. In contrast to previous approaches, which have attempted mainly to formalize the common service delivery models (i.e., Infrastructure-as-a-Service, Platform-as-a-Service, and Software-as-a-Service), in this work, we propose a formalism for describing common cloud usage scenarios referred to as cloud usage patterns. Our formalism takes a structuralist approach allowing decomposition of a cloud usage scenario into elements corresponding to the common cloud service delivery models. Furthermore, our formalism considers several cloud usage patterns that have recently emerged, such as hybrid services and value chains in which mediators are involved, also referred to as value chains with mediators. We propose a simple yet expressive textual and visual language for our formalism, and we show how it can be used in practice for describing a variety of real-world cloud usage scenarios. The scenarios for which we demonstrate our formalism include resource provisioning of global providers of infrastructure and/or platform resources, online social networking services, user-data processing services, online customer and ticketing services, online asset management and banking applications, CRM (Customer Relationship Management) applications, and online social gaming applications.

cs.DC↗

arXiv2014

On Benchmarking Intrusion Detection Systems in Virtualized Environments

Modern intrusion detection systems (IDSes) for virtualized environments are deployed in the virtualization layer with components inside the virtual machine monitor (VMM) and the trusted host virtual machine (VM). Such IDSes can monitor at the same time the network and host activities of all guest VMs running on top of a VMM being isolated from malicious users of these VMs. We refer to IDSes for virtualized environments as VMM-based IDSes. In this work, we analyze state-of-the-art intrusion detection techniques applied in virtualized environments and architectures of VMM-based IDSes. Further, we identify challenges that apply specifically to benchmarking VMM-based IDSes focussing on workloads and metrics. For example, we discuss the challenge of defining representative baseline benign workload profiles as well as the challenge of defining malicious workloads containing attacks targeted at the VMM. We also discuss the impact of on-demand resource provisioning features of virtualized environments (e.g., CPU and memory hotplugging, memory ballooning) on IDS benchmarking measures such as capacity and attack detection accuracy. Finally, we outline future research directions in the area of benchmarking VMM-based IDSes and of intrusion detection in virtualized environments in general.

cs.CR↗