@inproceedings{1592, abstract = {{Compared to classical HDL designs, generating FPGA with high-level synthesis from an OpenCL specification promises easier exploration of different design alternatives and, through ready-to-use infrastructure and common abstractions for host and memory interfaces, easier portability between different FPGA families. In this work, we evaluate the extent of this promise. To this end, we present a parameterized FDTD implementation for photonic microcavity simulations. Our design can trade-off different forms of parallelism and works for two independent OpenCL-based FPGA design flows. Hence, we can target FPGAs from different vendors and different FPGA families. We describe how we used pre-processor macros to achieve this flexibility and to work around different shortcomings of the current tools. Choosing the right design configurations, we are able to present two extremely competitive solutions for very different FPGA targets, reaching up to 172 GFLOPS sustained performance. With the portability and flexibility demonstrated, code developers not only avoid vendor lock-in, but can even make best use of real trade-offs between different architectures.}}, author = {{Kenter, Tobias and Förstner, Jens and Plessl, Christian}}, booktitle = {{Proc. Int. Conf. on Field Programmable Logic and Applications (FPL)}}, keywords = {{tet_topic_hpc}}, publisher = {{IEEE}}, title = {{{Flexible FPGA design for FDTD using OpenCL}}}, doi = {{10.23919/FPL.2017.8056844}}, year = {{2017}}, } @techreport{198, author = {{Jazayeri, Bahar and Platenius, Marie Christin and Engels, Gregor and Kundisch, Dennis}}, publisher = {{Universität Paderborn}}, title = {{{Features of IT Service Markets: A Systematic Literature Review (Supplementary Material)}}}, year = {{2016}}, } @inproceedings{199, abstract = {{The provision of IT solutions over electronic marketplaces became prominent in recent years. We call such marketplaces IT service markets. IT service markets have some core architectural building blocks that impact the quality attributes of these markets. However, these building blocks and their impacts are not well-known. Thus, design choices for IT service markets have been made ad-hoc until now. Furthermore, only single aspects of such markets have been investigated until now, but a comprehensive view is missing.In this paper, we identify common features and their interrelations on the basis of a systematic literature review of 60 publications using grounded theory.This knowledge provides an empirical evidence on the interdisciplinary design choices of IT service markets and it serves as a basis to support market providers and developers to integrate market features. Thereby, we make a first step towards the creation of a reference model for IT service markets that provides a holistic integrated view that can be used to create and maintain successful markets in the future.}}, author = {{Jazayeri, Bahar and Platenius, Marie and Engels, Gregor and Kundisch, Dennis}}, booktitle = {{Proceedings of the 14th International Conference on Service Oriented Computing (ICSOC)}}, pages = {{301--316}}, publisher = {{Springer}}, title = {{{Features of IT Service Markets: A Systematic Literature Review}}}, doi = {{10.1007/978-3-319-46295-0_19}}, volume = {{9936}}, year = {{2016}}, } @misc{213, author = {{Porzenheim, Laurens}}, publisher = {{Universität Paderborn}}, title = {{{Comparison of different Definitions of Chosen-Ciphertext Security in Encryption schemes}}}, year = {{2016}}, } @misc{214, author = {{Bemmann, Kai Sören}}, publisher = {{Universität Paderborn}}, title = {{{Commitment Schemes - Definitions, Variants, and Security}}}, year = {{2016}}, } @inproceedings{215, abstract = {{We present three robust overlay networks: First, we present a network that organizes the nodes into an expander and is resistant to even massive adversarial churn. Second, we develop a network based on the hypercube that maintains connectivity under adversarial DoS-attacks. For the DoS-attacks we use the notion of a Omega(log log n)-late adversary which only has access to topological information that is at least Omega(log log n) rounds old. Finally, we develop a network that combines both churn- and DoS-resistance. The networks gain their robustness through constant network reconfiguration, i.e., the topology of the networks changes constantly. Our reconguration algorithms are based on node sampling primitives for expanders and hypercubes that allow each node to sample a logarithmic number of nodes uniformly at random in O(log log n) communication rounds. These primitives are specific to overlay networks and their optimal runtime represents an exponential improvement over known techniques. Our results have a wide range of applications, for example in the area of scalable and robust peer-to-peer systems.}}, author = {{Drees, Maximilian and Gmyr, Robert and Scheideler, Christian}}, booktitle = {{Proceedings of the 28th ACM Symposium on Parallelism in Algorithms and Architectures (SPAA)}}, pages = {{417----427}}, title = {{{Churn- and DoS-resistant Overlay Networks Based on Network Reconfiguration}}}, doi = {{10.1145/2935764.2935783}}, year = {{2016}}, } @inproceedings{207, abstract = {{We consider a scheduling problem where machines need to be rented from the cloud in order to process jobs. There are two types of machines available which can be rented for machine-type dependent prices and for arbitrary durations. However, a machine-type dependent setup time is required before a machine is available for processing. Jobs arrive online over time, have machine-type dependent sizes and have individual deadlines. The objective is to rent machines and schedule jobs so as to meet all deadlines while minimizing the rental cost. Since we observe the slack of jobs to have a fundamental influence on the competitiveness, we study the model when instances are parameterized by their (minimum) slack. An instance is called to have a slack of $\beta$ if, for all jobs, the difference between the job's release time and the latest point in time at which it needs to be started is at least $\beta$. While for $\beta series = {LNCS}}}, author = {{Mäcker, Alexander and Malatyali, Manuel and Meyer auf der Heide, Friedhelm and Riechers, Sören}}, booktitle = {{Proceedings of the 10th Annual International Conference on Combinatorial Optimization and Applications (COCOA)}}, pages = {{578----592}}, title = {{{Cost-efficient Scheduling on Machines from the Cloud}}}, doi = {{10.1007/978-3-319-48749-6_42}}, year = {{2016}}, } @inproceedings{208, abstract = {{This paper presents a new framework for constructing fully CCA-secure predicate encryption schemes from pair encoding schemes. Our construction is the first in the context of predicate encryption which uses the technique of well-formedness proofs known from public key encryption. The resulting constructions are simpler and more efficient compared to the schemes achieved using known generic transformations from CPA-secure to CCA-secure schemes. The reduction costs of our framework are comparable to the reduction costs of the underlying CPA-secure framework. We achieve this last result by applying the dual system encryption methodology in a novel way.}}, author = {{Blömer, Johannes and Liske, Gennadij}}, booktitle = {{Proceedings of the CT-RSA 2016}}, pages = {{431--447}}, title = {{{Construction of Fully CCA-Secure Predicate Encryptions from Pair Encoding Schemes}}}, doi = {{10.1007/978-3-319-29485-8_25}}, year = {{2016}}, } @misc{223, abstract = {{We consider the problem of aggregation in overlay networks. We use a synchronous time model in which each node has polylogarithmic memory and can send at most a polylogarithmic number of messages per round. We investigate how to quickly compute the result of an aggregate functionf over elements that are distributed among the nodes of the network such that the result is eventually known by a selected root node. We show how to compute distributive aggregate functions such as SUM, MAX, and OR in time $O(\log n / \log\log n)$ using a tree that is created in a pre-processing phase. If only a polylogarithmic number of data items need to be aggregated, we show how to compute the result in time $O(\sqrt{\log n / \log\log n})$. Furthermore, we show how to compute holistic aggregate functions such as DISTINCT, SMALLEST(k) and MODE(k) in time $O(\log n / \log\log n)$. Finally, we show a lower bound of $\Omega(\sqrt{\log n / \log\log n})$ for deterministic algorithms that compute any of the aggregate functions in the scope of the thesis.}}, author = {{Hinnenthal, Kristian}}, publisher = {{Universität Paderborn}}, title = {{{Aggregation in Overlay Networks}}}, year = {{2016}}, } @inproceedings{219, abstract = {{Existing software markets like Google Play allow users to search among available Apps and select one based on the description provided for the App or based on its rating. Future software markets facilitate on-the-fly composition of such Apps based on users’ individual wishes. Realizing such On-The-Fly Computing (OTF) markets requires support of sophisticated software features. In addition, suitable orchestration among such features needs to ensure well-alignment of business and IT aspects in case of run-time changes like market dynamics. However, all these introduce new architectural and management complexities, which are specific to such markets. An architecture framework for OTF markets will include design solutions to overcome these complexities. In my PhD, I aim at identifying an architecture framework for OTF markets including main architectural building blocks and a systematic development process. Such an architecture framework enables the development of OTF markets in the future. Furthermore, this knowledge can be used as a basis to improve existing software markets by integrating missing functionalities.}}, author = {{Jazayeri, Bahar}}, booktitle = {{Proceedings of the 10th European Conference on Software Architecture (ECSA Workshops)}}, pages = {{42}}, publisher = {{ACM}}, title = {{{Architectural Management of On-The-Fly Computing Markets}}}, doi = {{10.1145/2993412.3010821}}, year = {{2016}}, } @phdthesis{220, author = {{Keller, Matthias}}, publisher = {{Universität Paderborn}}, title = {{{Application Deployment at Distributed Clouds}}}, year = {{2016}}, } @article{726, author = {{Wette, Philip and Karl, Holger}}, journal = {{Computer Communications}}, pages = {{45----58}}, title = {{{DCT²Gen: A traffic generator for data centers}}}, doi = {{10.1016/j.comcom.2015.12.001}}, year = {{2016}}, } @inproceedings{730, abstract = {{Allocating resources to virtualized network functions and services to meet service level agreements is a challenging task for NFV management and orchestration systems. This becomes even more challenging when agile development methodologies, like DevOps, are applied. In such scenarios, management and orchestration systems are continuously facing new versions of functions and services which makes it hard to decide how much resources have to be allocated to them to provide the expected service performance. One solution for this problem is to support resource allocation decisions with performance behavior information obtained by profiling techniques applied to such network functions and services. In this position paper, we analyze and discuss the components needed to generate such performance behavior information within the NFV DevOps workflow. We also outline research questions that identify open issues and missing pieces for a fully integrated NFV profiling solution. Further, we introduce a novel profiling mechanism that is able to profile virtualized network functions and entire network service chains under different resource constraints before they are deployed on production infrastructure.}}, author = {{Peuster, Manuel and Karl, Holger}}, booktitle = {{Fifth European Workshop on Software-Defined Networks, EWSDN 2016, Den Haag, The Netherlands, October 10-11, 2016}}, location = {{Den Haag}}, pages = {{7----12}}, title = {{{Understand Your Chains: Towards Performance Profile-Based Network Service Management}}}, doi = {{10.1109/EWSDN.2016.9}}, year = {{2016}}, } @inproceedings{731, abstract = {{Traditional cellular networks are forced to remain active regardless of the actual amount of traffic that is currently produced/requested, with a clear waste of energy. Two-layer mobile networks with separated signalling and data layers have been recently proposed for energy savings in future implementations. These networks are able to switch off unneeded data cells completely while maintaining full coverage with their signalling cells, thus saving energy. In this demonstration, we showcase a testbed that uses Wi-Fi access points to emulate small cells of the data layer and a publicly available cellular connection as the signalling layer. We use off-the-shelf Android smartphones with an ad-hoc networking management module and a MultiPath TCP-enabled kernel to manage the Wi-Fi and cellular interfaces simultaneously. The testbed is used to demonstrate the general feasibility of this layered architecture and to facilitate experiments with network-wide resource optimization. }}, author = {{Peuster, Manuel and Karl, Holger and Enrico Redondi, Alessandro and Capone, Antonio}}, booktitle = {{IEEE Conference on Computer Communications Workshops, INFOCOM Workshops 2016, San Francisco, CA, USA, April 10-14, 2016}}, location = {{San Francisco}}, pages = {{1015----1016}}, title = {{{Demonstrating on-demand cell switching with a two-layer mobile network testbed}}}, doi = {{10.1109/INFCOMW.2016.7562232}}, year = {{2016}}, } @inproceedings{738, abstract = {{Virtualized network services consisting of multiple individual network functions are already today deployed across multiple sites, so called multi-PoP (points of presence) environments. This allows to improve service performance by optimizing its placement in the network. But prototyping and testing of these complex distributed software systems becomes extremely challenging. The reason is that not only the network service as such has to be tested but also its integration with management and orchestration systems. Existing solutions, like simulators, basic network emulators, or local cloud testbeds, do not support all aspects of these tasks. To this end, we introduce MeDICINE, a novel NFV prototyping platform that is able to execute production-ready network functions, provided as software containers, in an emulated multi-PoP environment. These network functions can be controlled by any third-party management and orchestration system that connects to our platform through standard interfaces. Based on this, a developer can use our platform to prototype and test complex network services in a realistic environment running on his laptop. }}, author = {{Peuster, Manuel and Karl, Holger and van Rossem, Steven}}, booktitle = {{IEEE Conference on Network Function Virtualization and Software Defined Networks (NFV-SDN)}}, location = {{Palo Alto}}, title = {{{MeDICINE: Rapid Prototyping of Production-Ready Network Services in Multi-PoP Environments}}}, doi = {{10.1109/NFV-SDN.2016.7919490}}, year = {{2016}}, } @misc{5418, author = {{Tölke, Christian}}, publisher = {{Universität Paderborn}}, title = {{{Sicherheit von hybriden FPGA-Systemen in der industriellen Automatisierungstechnik -- Anforderungen und Umsetzung}}}, year = {{2016}}, } @misc{5420, author = {{Wüllrich, Gunnar}}, publisher = {{Universität Paderborn}}, title = {{{Dynamic OpenCL Task Scheduling for Energy and Performance in a Heterogeneous Environment}}}, year = {{2016}}, } @inproceedings{166, abstract = {{Network function virtualization and software-defined networking allow services consisting of virtual network functions to be designed and implemented with great flexibility by facilitating automatic deployments, migrations, and reconfigurations for services and their components. For extended flexibility, we go beyond seeing services as a fixed chain of functions. We present a YANG model for describing the service structure in deployment requests in a flexible way that enables changing the order of functions in case the order of traversing them does not affect the functionality of the service. Upon receiving such requests, the network orchestration system can choose the optimal composition of service components that gives the best results for placement of services in the network. This introduces new complexities to the placement problem by greatly increasing the number of possible ways a service can be composed. In this paper, we describe a heuristic solution that selects a Pareto set of the possible compositions of a service as well as possible combinations of different services, with respect to different resource requirements of the services. Our evaluations show that the selected combinations consist of representative samples of possible structures and requirements and therefore, can result in optimal or close-to-optimal placement results.}}, author = {{Dräxler, Sevil and Karl, Holger}}, booktitle = {{Proceedings of the 2nd International IEEE Conference on Network Softwarization (NetSoft)}}, pages = {{184----192}}, title = {{{Placement of Services with Flexible Structures Specified by a YANG Data Model}}}, doi = {{10.1109/NETSOFT.2016.7502412}}, year = {{2016}}, } @phdthesis{167, author = {{Günther, Peter}}, publisher = {{Universität Paderborn}}, title = {{{Physical attacks on pairing-based cryptography}}}, year = {{2016}}, } @phdthesis{172, author = {{Stapel, Florian}}, publisher = {{Universität Paderborn}}, title = {{{Ontology-based representation of abstract optimization models for model formulation and system generation}}}, year = {{2016}}, }