Now showing 1 - 10 of 73
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Comparison of Ethereum Smart Contract Analysis and Verification Methods

2024 , Happersberger, Vincent , Jäkel, Frank-Walter , Knothe, Thomas , Pignolet, Yvonne Anne , Schmid, Stefan

Ethereum allows to publish and use applications known as smart contracts on its public network. Smart contracts can be costly for users if erroneous. Various security vulnerabilities have occurred in the past and have been exploited causing the loss of billions of dollars. Therefore, it is in the developer’s interest to publish smart contracts that serve their intended purpose only. In this work, we study different approaches to verify if Ethereum smart contracts behave as intended and how to detect possible vulnerabilities. To this end, we compare and evaluate, different formal verification tools and tools to automatically detect vulnerabilities. Our empirical comparison of 140 smart contracts with known vulnerabilities shows that different tools vary in their success to identify issues with smart contracts. In general, we find that automated analysis tools often miss vulnerabilities, while formal verifiers based on model checking with Hoare-style source code annotations require high effort and knowledge to discover possible weaknesses. Specifically, some vulnerabilities (e.g., related to bad randomness) are not detected by any of the tools. Formal verifiers perform better than automated analysis tools as they detect more vulnerabilities and are more reliable. One of the automated analysis tools was able to find only three out of 16 Access Control vulnerabilities. On the contrary, formal verifiers have a hundred percent detection rate for selected tests. As a case study with a smart contract without previously known vulnerabilities and for a more in-depth evaluation, we examine a smart contract using a two-phase commit protocol mechanism which is key in many smart contract applications. We use the presented tools to analyze and verify the contract. Thereby we come across different important patterns to detect vulnerabilities e.g. with respect to re-entrancy, and how to annotate a contract to prove that intended the restriction and requirements hold at any time.

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Datendurchgängige Fabrik. Eine Blaupause zur Planung von Fabriken

2023 , Ihnen, Deike Magret , Lange, Annika , Knothe, Thomas

Das Blue Print Plant Model ist ein integriertes Unternehmensmodell, welches Objekte und deren Parameter einer Fabrik mit Prozessen sowie den Berechnungs- und Auslegungsverfahren verbindet. Dabei werden Partikularmodelle, wie zum Beispiel Wirtschaftlichkeitsanalysen, flexibel eingebunden. Die integrierte Betrachtung unterstützt eine Datendurchgängigkeit, mit der sich Medienbrüche entlang der Planungsphasen reduzieren lassen. Im Beitrag werden Erfahrungen anhand eines Use Cases der diskreten Fertigung dargestellt.

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Model based Configuration of Platforms for Managing Cross-Organizational (Business) Processes

2022 , Knothe, Thomas , Gering, Patrick , Glodde, Ilona , Ahle, Ulrich , Böttger, Jonas , Döberitz, Niklas

In this contribution interoperability is considered from the perspective of platforms, which have to manage cross-organisational business processes. A model-based approach for configuring a cloud platform for managing complex processes and their dependencies across different organisations is provided. The approach is applied on using FIWARE, which provides a framework of open source software platform components. The core concept is to extend the open source core data model of FIWARE by using the artefacts of an Enterprise model, describing the dependencies of processes, roles, object data and application interfaces. Based on a given use case the principal configuration was applied and validated.

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Synchronisierte Modularisierung in der Fertigung

2022 , Torka, Jan , Kohl, Holger , Knothe, Thomas , Goppold, Jean-Paul

Modularization has long been considered one of the basic characteristics of adaptable production systems. However, the implementation of modularization of equipment, processes, and shop floor IT is challenging today. This paper presents an integrated methodology for the development of modularized production and the shop floor IT that controls it, using assembly as an example. Starting from the economic goals, the joint development and implementation of the assembly and shop floor IT modules are based on an integrated model.

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Blue Print Plant Model. Ein Modell zur Unterstützung des Fabrikplanungsprozesses

2023 , Lange, Annika , Ihnen, Deike Magret , Knothe, Thomas

In den letzten beiden Dekaden sind die Unsicherheiten und Abhängigkeiten externer Faktoren bei der Fabrikplanung gestiegen. Immer relevanter wird eine Datendurchgängigkeit, die quer zu den Planungsphasen verbessert wird, sodass externe und interne Änderungen sowie deren Auswirkungen auf die Planungsobjekte einfacher und schneller bewertet werden können. In dem Beitrag wird ein Konzept vorgestellt, welches mithilfe eines verteilten digitalen Fabrikzwillings, bereits in der frühen Planungsphase die Durchgängigkeit unterstützt. Die Vernetzung der Komponenten wird durch ein Unternehmensmodell realisiert, das entlang des Fabriklebenszyklus aufgebaut und angewendet wird.

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The Use of Digital Twins to Overcome Semantic Barriers in Hyperconnected Ecosystems for Industry

2022 , Jäkel, Frank-Walter , Gering, Patrick , Knothe, Thomas

To establish business networks a match between businesses demands and potential partner information is required. Publicly available information on the Internet about companies, products and services usually don’t follow a common standard. The concept of a digital twin could be used to organise the different information and, in the future, to harmonise the way company data is made available on the web. Every company usually has a web presence, related documents, web pages and a trace on the web, which can be used for an initial structure of the digital twin. Hereby, first services for the correlations between partner companies and requirements can be designed. But it requires the management of legal aspects e.g. the access of bots to the public available information. The paper provides initial ideas and feasibility checks and it propose an evolution of the current heterogeneous content and structure of the data into a well-structured digital twin including content related ontologies to describe the company characteristics.

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Bioinspirierte Erkennung von Abweichungen: Erweiterung des Interaktiven Lagebildes um einen bionisch basierten Disruptionsmodus

2022 , Lange, Annika , Gering, Patrick , Agacayaklar, Irfan Furkan , Knothe, Thomas , Busse, Dirk

Companies must constantly adapt to changes in their environment. Disruptions can occur in a company. For example, there were supply bottlenecks during the COVID 19 pandemic. In order to identify such disruptions at an early stage and to initiate alternative measures, the further development of the interactive situation awarness monitor is described in this paper.

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Integrated Model-Based Configuration of Production Systems - Reflection of ISO 19440 and MDA and MDI

2023 , Knothe, Thomas , Torka, Jan , Gering, Patrick , Jäkel, Frank-Walter

Rising business competition leads to complexity because of increased number of product variants and customer-specific processes. Model-based approaches seem to be suitable for handling this kind of flexibility in networked production environments. In this paper, current approaches to the configuration of heterogeneous systems based on standard models are reflected, and an integrated model-based configuration approach using formalized modules is proposed and its application demonstrated.

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Interoperability Challenges and Solutions within Industrial Networks

2022 , Jäkel, Frank-Walter , Knothe, Thomas

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Biological transformation: Principles to enhance holistic production systems

2022 , Lange, Annika , Knothe, Thomas , Kohl, Holger , Seliger, Guenther

In today's production systems, the digital transformation is fully in progress. But the next evolution step can be seen on the horizon, biological transformation. This means the application of biomimetics principles with the aim of low-effort, resource-saving, reversible and adapted economies. Because of their aim regarding minimization of resource consumption and stability orientation even in turbulent environments, biomimetics principles can contribute to the major challenges of production systems, climate change, environmental protection, as well as the turbulences as generated by globalization and individualization in this paper it is described how biological transformation can contribute to extend and improve holistic production systems. For this purpose, traditional principles of holistic production systems are reflected with the ones coming from digitization and biomimetics.