@inproceedings{MuenchFrauenschlaegerMottok, author = {M{\"u}nch, Andreas and Frauenschl{\"a}ger, Tobias and Mottok, J{\"u}rgen}, title = {Integration of a Security Gateway for Critical Infrastructure into Existing PKI Systems}, series = {3. Symposium Elektronik und Systemintegration (ESI 2022), Tagungsband: 06. April 2022, Hochschule Landshut, Deutschland}, booktitle = {3. Symposium Elektronik und Systemintegration (ESI 2022), Tagungsband: 06. April 2022, Hochschule Landshut, Deutschland}, publisher = {Hochschule Landshut}, address = {Landshut}, isbn = {978-3-9818439-7-2}, pages = {88 -- 97}, language = {en} } @inproceedings{FritzSchmidMottok, author = {Fritz, Florian and Schmid, Michael and Mottok, J{\"u}rgen}, title = {Accelerating Real-Time Applications with Predictable Work-Stealing}, series = {Architecture of computing systems - ARCS 2020: 33rd international conference, Aachen, Germany, May 25-28, 2020, proceedings}, booktitle = {Architecture of computing systems - ARCS 2020: 33rd international conference, Aachen, Germany, May 25-28, 2020, proceedings}, editor = {Brinkmann, Andr{\´e}}, doi = {10.1007/978-3-030-52794-5_18}, pages = {241 -- 255}, abstract = {Modern compute architectures often consist of multiple CPU cores to achieve their performance, as physical properties put a limit on the execution speed of a single processor. This trend is also visible in the embedded and real-time domain, where programmers are forced to parallelize their software to keep deadlines. Additionally, embedded systems rely increasingly on modular applications, that can easily be adapted to different system loads and hardware configurations. To parallelize applications under these dynamic conditions, often dispatching frameworks like Threading Building Blocks (TBB) are used in the desktop and server segment. More recently, Embedded Multicore Building Blocks (EMB2) was developed as a task-based programming solution designed with the constraints of embedded systems in mind. In this paper, we discuss how task-based programming fits such systems by analyzing scheduler implementation variants, with a focus on classic work-stealing and the libraries TBB and EMB2. Based on the state of the art we introduce a novel resource-trading concept that allows static memory allocation in a work-stealing runtime holding strict space and time bounds. We conduct benchmarks between an early prototype of the concept, TBB and EMB2, showing that resource-trading does not introduce additional runtime overheads, while unfortunately also not improving on execution time variances.}, language = {en} } @inproceedings{FrauenschlaegerRennerMottok, author = {Frauenschl{\"a}ger, Tobias and Renner, Sebastian and Mottok, J{\"u}rgen}, title = {Security Improvements by Separating the Cryptographic Protocol from the Network Stack onto a Multi-MCU Architecture}, series = {Architecture of Computing Systems - ARCS 2020: 33rd international conference, Aachen, Germany, May 25-28, 2020, proceedings}, booktitle = {Architecture of Computing Systems - ARCS 2020: 33rd international conference, Aachen, Germany, May 25-28, 2020, proceedings}, publisher = {Springer International Publishing}, doi = {10.1007/978-3-030-52794-5_14}, pages = {185 -- 199}, abstract = {The number of IoT devices in SCADA and ICS systems is rising quickly, especially in the domain of critical infrastructures. But these kinds of systems are performing mission critical tasks like controlling devices in industrial facilities or substations in the smart grid. Therefore, they are subject to a lot of regulatory standards. Yet, to provide remote access over the internet, special architectures are developed to integrate a network interface into these devices without inferring with the actual functionality. However, these architectures either lack security measures against cyber-attacks or do not offer the necessary performance for time-critical communication interfaces. To solve that, an architecture consisting of three units is introduced in this paper to provide a network interface with extensive security measures and a high performance. The main feature is the isolation of the cryptographic functionality onto an additional MCU. After proposing the basic concept, the paper presents many implementation details. Based on the current state of implementation, a concept validation of the realized architecture is described.}, language = {en} } @inproceedings{SchmidFritzMottok, author = {Schmid, Michael and Fritz, Florian and Mottok, J{\"u}rgen}, title = {Parallel Programming in Real-Time Systems}, series = {Architecture of computing systems - ARCS 2019, 32nd international conference, Copenhagen, Denmark, May 20-21, 2019, proceedings}, booktitle = {Architecture of computing systems - ARCS 2019, 32nd international conference, Copenhagen, Denmark, May 20-21, 2019, proceedings}, publisher = {VDE-Verlag}, address = {Berlin}, abstract = {The enormous amounts of data modern real-time systems have to process lead to expensive, long-lasting calculations. In order to manage those computations in a timely manner, parallel task models have gained a lot of popularity lately. However, parallel programming can be very cumbersome and verbose. Other computationally intensive sectors have dealt with parallel computing for decades and have accumulated their experience in the development of parallel frameworks. Examples of well known parallel runtime systems are OpenMP, Intel Threading Building Blocks (TBB) and Microsoft Parallel Pattern Library (PPL). These runtime systems allow developers to enhance parallelism in their applications in a straightforward fashion. However, those parallel frameworks and the patternbased interfaces they provide might not be easily applicable in real-time systems. In this paper, we investigate the use of parallel programming frameworks in time-critical systems. On that account, we discuss considerations for the design of real-time applications that make use of such parallel runtime systems. Furthermore, we evaluate three library-based frameworks from different computing sectors, namely Intel Threading Building Blocks, Embedded Multicore Building Blocks (EMBB) and High Performance ParalleX (HPX), by conducting benchmarks of various parallel algorithms on an embedded multicore architecture.}, language = {en} } @inproceedings{OsinskiMottok, author = {Osinski, Lukas and Mottok, J{\"u}rgen}, title = {S 3DES - Scalable Software Support for Dependable Embedded Systems}, series = {Architecture of Computing Systems - ARCS 2019, 32nd International Conference, Copenhagen, Denmark, May 20-23, 2019, Proceedings}, booktitle = {Architecture of Computing Systems - ARCS 2019, 32nd International Conference, Copenhagen, Denmark, May 20-23, 2019, Proceedings}, editor = {Schoeberl, Martin and Hochberger, Christian and Uhrig, Sascha and Brehm, J{\"u}rgen and Pionteck, Thilo}, publisher = {Springer}, address = {Cham}, doi = {10.1007/978-3-030-18656-2_2}, pages = {15 -- 27}, abstract = {Scalable Software Support for Dependable Embedded Systems (S3DES) achieves fault tolerance by utilizing spatial software-based triple modular redundancy for computational and voter processes on application level. Due to the parallel execution of the replicas on distinct CPU cores it makes a step towards software-based fault tolerance against transient and permanent random hardware errors. Additionally, the compliance with real-time requirements in terms of response time is enhanced compared to similar approaches. The replicated voters, the introduced mutual voter monitoring and the optimized arithmetic encoding allow the detection and compensation of voter failures without the utilization of backward recovery. Fault injection experiments on real hardware reveal that S3DES can detect and mask all injected data and program flow errors under a single fault assumption, whereas an uncoded voting scheme yields approx. 12\% silent data corruptions in a similar experiment.}, language = {en} } @inproceedings{WaegemannLangerMottoketal., author = {Waegemann, Tobias and Langer, Tobias and Mottok, J{\"u}rgen and Osinski, Lukas and Stappert, Friedhelm and Tayakoli Kolagari, Ramin}, title = {Models for Dependable Heterogenous Multi- and Many-Core System Software Design Revisited}, series = {ARCS 2016, 29th International Conference on Architecture of Computing Systems, 4-7 April 2016, Nuremberg, Germany}, booktitle = {ARCS 2016, 29th International Conference on Architecture of Computing Systems, 4-7 April 2016, Nuremberg, Germany}, abstract = {Modelling approaches have to satisfy certain criteria in order to sufficiently encompass the characteristics of dependable heterogenous multi- and many-core system architectures. This work-in-progress paper gives an overview of modern modelling approaches and their related research projects, particularly those regarding domain specific architecture description languages, as well as of the specific challenges of dependable systems and heterogenous multi- and many-core designs, i.e. scheduling techniques for real-time requirements and concerns regarding functional safety. Furthermore, an ongoing research effort in order to identify a set of criteria for evaluating the eligibility of modelling approaches for the task of adequately representing these systems and their specific characteristics is presented.}, language = {en} } @inproceedings{LangerOsinskiMottok, author = {Langer, Tobias and Osinski, Lukas and Mottok, J{\"u}rgen}, title = {A Survey of Parallel Hard-Real Time Scheduling on Task Models and Scheduling Approaches}, series = {ARCS 2017; 30th International Conference on Architecture of Computing Systems, 3-6 April 2017, Vienna, Austria}, booktitle = {ARCS 2017; 30th International Conference on Architecture of Computing Systems, 3-6 April 2017, Vienna, Austria}, abstract = {The trend towards multi-core systems becomes increasinglyomnipresentandhasalreadyreachedhardreal-time systems. In the recent years more and more researchers tackle the problem of scheduling parallel tasks with real-time constraints. We present a discussion of these recent approaches to hard real-time scheduling tasks consisting of multiple threads. We identify categories in scheduling mechanisms and task systems and discuss their features, as well as the research already achieved in their ???elds. In the domain of task models we identi???ed the gang constrained task model, the order constrained task model and the unconstrained task model. These task models differ regardingtheamountandtypeofthreadexecutionconstraints, which can be expressed using the model. Regarding scheduling algorithms, we identi???ed transformation based and nontransformation based scheduling schemes. The former rely on off-line task transformation, whereas the latter doesn???t require any prior information about task structures. The presented classi???cations show, that applied scheduling algorithms mostly are not restricted to certain task models, but that they are applied quite independently.}, language = {en} } @inproceedings{SchmidMottok, author = {Schmid, Michael and Mottok, J{\"u}rgen}, title = {Asynchronous Critical Sections in Real-Time Multiprocessor Systems}, series = {Architecture of Computing Systems - ARCS 2019, 32nd International Conference, Copenhagen, Denmark, May 20-23, 2019, Proceedings}, booktitle = {Architecture of Computing Systems - ARCS 2019, 32nd International Conference, Copenhagen, Denmark, May 20-23, 2019, Proceedings}, editor = {Schoeberl, Martin and Hochberger, Christian and Uhrig, Sascha and Brehm, J{\"u}rgen and Pionteck, Thilo}, publisher = {Springer}, address = {Cham}, doi = {10.1007/978-3-030-18656-2_5}, pages = {56 -- 67}, abstract = {Sharing data across multiple tasks in multiprocessor systems has intensively been studied in the past decades. Various synchronization protocols, the most well-known being the Priority Inheritance Protocol or the Priority Ceiling Protocol, have been established and analyzed so that blocking times of tasks waiting to access a shared resource can be upper bounded. To the best of our knowledge, all of these protocols share one commonality: Tasks that want to enter a critical section, that is already being executed by another task, immediately get blocked. In this paper, we introduce the Asynchronous Priority Ceiling Protocol (A-PCP), which makes use of aperiodic servers to execute the critical sections asynchronously, while the calling task can continue its work on non-critical section code. For this protocol, we provide a worst-case response time analysis of the asynchronous computations, as well as necessary and sufficient conditions for a feasibility analysis of a set of periodic tasks using the proposed synchronization model on a system that preemptively schedules the tasks under the rate-monotonic priority assignment.}, language = {en} } @inproceedings{RennerMottok, author = {Renner, Sebastian and Mottok, J{\"u}rgen}, title = {Towards Key Management Challenges in the Smart Grid}, series = {ARCS Workshop 2019 - 32nd International Conference on Architecture of Computing Systems, 20-21 May 2019, Copenhagen, Denmark}, booktitle = {ARCS Workshop 2019 - 32nd International Conference on Architecture of Computing Systems, 20-21 May 2019, Copenhagen, Denmark}, editor = {Trinitis, Carsten and Pionteck, Thilo}, publisher = {VDE-Verlag}, address = {Berlin}, isbn = {978-3-8007-4957-7}, abstract = {The used technology in the power system is subject of great change. Through the use of smart devices, the systems in the power grid get interconnected between each other and remote networks. Especially the remote access to the critical smart grid environment involves new challenges in the area of security. To ensure the transmitted data and the access to the system is secured, cryptographic mechanisms have to be implemented. One critical part in this task is the management of cryptographic keys. This paper explains and defines a set of basic requirements for cryptographic key management in the smart grid. These requirements are derived from challenges present in common corporate environments. Then, basic approaches in the field of key management are stated and evaluated for the applicability in the power system. Different protocols for the implementation of key management strategies are shown and an assessment regarding their suitability for the defined requirements is conducted.}, language = {en} } @inproceedings{SchmidMottok, author = {Schmid, Michael and Mottok, J{\"u}rgen}, title = {Investigation of Scheduling Algorithms for DAG. Tasks through Simulations}, series = {ERTS 2022, 11th European Congress Embedded Real Time Systems: 1-2 June, Toulouse, France}, booktitle = {ERTS 2022, 11th European Congress Embedded Real Time Systems: 1-2 June, Toulouse, France}, pages = {9}, abstract = {In the real-time systems sector, various task models and corresponding tests exist to model and verify the schedulability of task sets on the system at hand. While those models and schedulability tests have intensively been studied from a theoretical point of view, it is hard to ma e use of them to compare the actual execution behavior of scheduling algorithms on a real system. In contrast to schedulability tests, simulators can help to investigate the performance of specific scheduling algorithms. One of the most generalized task models to describe parallel tasks is the Directed Acyclic Graph model that allows to represent tasks as a series of subtasks that depict the potentially parallel computations and precedence constraints that denote the order in which the subtasks are allowed to execute. In this paper, we investigate various scheduling algorithms for the Directed Acyclic Graph model. For that, we first recapitulate the examined scheduling algorithms in detail and point out relevant differences. Subsequently, we present the evaluation of different global and federated scheduling algorithms using fine-grained parallel tasks. To this end, we generate random Directed Acyclic Graph tasks and simulate their execution on multiprocessor systems using scheduling algorithms such as global rate-monotonic and semi-federated scheduling as well as global scheduling policies using the thread pool model.}, language = {en} } @misc{RennerPozzobonMottok, author = {Renner, Sebastian and Pozzobon, Enrico and Mottok, J{\"u}rgen}, title = {3rd Round Ciphers Evaluation on Microcontrollers}, series = {Lightweight Cryptography Workshop (virtual): May 9-11 2022}, journal = {Lightweight Cryptography Workshop (virtual): May 9-11 2022}, publisher = {National Institute of Standards and Technology (NIST)}, address = {Gaithersburg}, language = {en} } @inproceedings{DeNiklasRooneyetal., author = {De, Sangita and Niklas, Michael and Rooney, Brian and Mottok, J{\"u}rgen and Brada, Premek}, title = {Towards Semantic model-to-model Mapping of Cross-Domain Component Interfaces for Interoperability of Vehicle Applications : An Approach towards Synergy Exploration}, series = {MDE4IoT \& ModComp 2019: Model-Driven Engineering for the Internet of Things (MDE4IoT) \& Interplay of Model-Driven and Component-Based Software Engineering (ModComp); joint proceedings of the Workshop on Model-Driven Engineering for the Internet of Things (MDE4IoT) \& of the Workshop on Interplay of Model-Driven and Component-Based Software Engineering (ModComp); co-located with the IEEE/ACM 22nd International Conference on Model Driven Engineering Languages and Systems (MODELS 2019), Munich, Germany, September 15 and 17, 2019}, booktitle = {MDE4IoT \& ModComp 2019: Model-Driven Engineering for the Internet of Things (MDE4IoT) \& Interplay of Model-Driven and Component-Based Software Engineering (ModComp); joint proceedings of the Workshop on Model-Driven Engineering for the Internet of Things (MDE4IoT) \& of the Workshop on Interplay of Model-Driven and Component-Based Software Engineering (ModComp); co-located with the IEEE/ACM 22nd International Conference on Model Driven Engineering Languages and Systems (MODELS 2019), Munich, Germany, September 15 and 17, 2019}, publisher = {RWTH Aachen}, address = {Aachen}, doi = {10.13140/RG.2.2.28765.15840}, abstract = {With the increase in demand of services in the automotive industry, automotive enterprises prefer to collaborate with other qualified cross-domain partners to provide complex automotive functions (or services), such as autonomous driving, OTA (Over The Air) vehicle update, V2X (Vehicle-to-Vehicle communication), etc. One key element in cross-domain enterprise collaboration is the mutual agreement between interfaces of software components. In this context, model-to-model mappings of software component models of heterogeneous frameworks for automotive services and to explore the synergies in their interface semantics, have become an essential factor in improving the interoperability among the automotive and other cross-domain enterprises. However, one of the challenges in achieving cross-domain component interface model-to-model mappings at an application level lies in detecting the interface semantics and the semantic relations that are conveyed in different component models in different frameworks. This paper addresses this challenge using a Model Driven Architecture (MDA) based analytical approach to explore interface semantic synergies in the cross-domain component meta-models that are used for automotive services. The approach applies manual semantic checking measurements at an application interface level to understand the meanings and relations between the different meta-model entities of cross-domain framework software components. In this research, we attempt to ensure that interface description models of software components from heterogeneous frameworks can be compared, correlated and re-used for automotive services based on semantic synergies. We have demonstrated our approach using component meta-models from cross-domain enterprises, that are used for the automotive application domain.}, language = {en} } @inproceedings{DeMottokBrada, author = {De, Sangita and Mottok, J{\"u}rgen and Brada, Premek}, title = {Evaluation of Semantic Interoperability of Automotive Service API Models Based on Metamodels Similarity Metrics Using a Semi-automated Approach}, series = {iCETiC 2022 : 5th International Conference on Emerging Technologies in Computing 2022: Aug 15, 2022 - Aug 16, 2022, Chester, UK}, booktitle = {iCETiC 2022 : 5th International Conference on Emerging Technologies in Computing 2022: Aug 15, 2022 - Aug 16, 2022, Chester, UK}, editor = {Miraz, M.H. and Southall, G. and Ali, Maaruf and Ware, A.}, publisher = {Springer}, address = {Cham}, doi = {10.1007/978-3-031-25161-0_2}, pages = {14 -- 28}, abstract = {In recent years, mapping of application software components' ontologies semantically emerged as a big research challenge in automotive application domain that manipulates several cross-enterprise synergy knowledge application frameworks. The same knowledge formalized by different experts in different vehicle application frameworks leads to heterogeneous representations of components' interface data. Consequently, this causes the most daunting impediment in semantic interoperability between the service components in cooperative automotive systems. From a modeling perspective, in the absence of standardized domain-based unified modeling techniques, the orchestration and resolution of semantic data interoperability between various vehicle application frameworks' components' interface models remain a challenge. However, this challenge could be addressed using ontological metamodeling by specifying semantic associations between components' interface model concepts based on the domain knowledge. Apart from the semantic mapping of interface ontological metamodels, this work also defines quality metrics to determine the degree of semantic alignment achieved between the various interface ontologies. Additionally, to reduce development time and cost towards semantic interoperability, this work proposes a semi-automated plugin tool for the applicability of the evaluated quality metrics to semantic mapping of real-world components' interface models.}, language = {en} }