Jaroslaw Sugier

Complex Systems and Dependability

Typical contemporary complex system is a multifaceted amalgamation of technical, information, organization, software and human (users, administrators and management) resources. Complexity of such a system comes not only from its involved technical and organizational structure but mainly from complexity of information processes that must be implemented in the operational environment (data processing, monitoring, management, etc.). In such case traditional methods of reliability analysis focused mainly on technical level are usually insufficient in performance evaluation and more innovative methods of dependability analysis must be applied which are based on multidisciplinary approach to theory, technology and maintenance of systems operating in real (and very often unfriendly) environments. This monograph presents selected new developments in such areas of dependability research as system modelling, tools and methodologies for system analysis, data security, secure system design and specific dependability aspects in specialized technical applications. Many practical cases illustrate the universal rule that complexity and multiplicity of system processes, their concurrency and their reliance on embedded intelligence (human and artificial) significantly impedes construction of strict mathematical models and calls for application of intelligent and soft computing methods.

New Results in Dependability and Computer Systems

DepCoS RELCOMEX is an annual series of conferences organized by the Institute of Computer Engineering, Control and Robotics (CECR), Wrocaw University of Technology, since 2006. Its idea came from the heritage of the other two cycles of events: RELCOMEX Conferences (1977 89) and Microcomputer Schools (1985 95) which were then organized by the Institute of Engineering Cybernetics, the previous name of CECR. In contrast to those preceding meetings focused on the conventional reliability analysis, the DepCoS mission is to develop a more comprehensive approach to computer system performability, which is now commonly called dependability. Contemporary technical systems are integrated unities of technical, information, organization, software and human resources. Diversity of the processes being realized in the system, their concurrency and their reliance on in-system intelligence significantly impedes construction of strict mathematical models and calls for application of intelligent and soft computing methods. The submissions included in this volume illustrate variety of problems that need to be explored in the dependability analysis: methodologies and practical tools for modeling, design and simulation of the systems, security and confidentiality in information processing, specific issues of heterogeneous, today often wireless, computer networks, or management of transportation networks.

Modeling Changes in Maintenance Activities through Fine-Tuning Markov Models of Ageing Equipment

Markov models are well established technique used widely for modeling equipment deterioration. This work presents an approach where Markov models represent equipment ageing and also incorporate various maintenance activities. Having available some basic model representing both deterioration and maintenance processes it is possible to adjust its parameters so that it corresponds to some hypothetical new maintenance policy and then to examine impact that this new policy has on various reliability characteristics of the system. The paper presents a method of model adjustment and discusses implementation of three numerical algorithms solving the problem of parameter approximation. A practical example confirms validity of the approach and illustrates its efficiency.

Theory and Engineering of Complex Systems and Dependability

Building upon a long tradition of scientifi c conferences dealing with problems ofreliability in technical systems, in 2006 Department of Computer Engineering atWrocaw University of Technology established DepCoS-RELCOMEX series of eventsin order to promote a comprehensive approach to evaluation of system performabilitywhich is now commonly called dependability.Contemporary complex systems integrate variety of technical, information, soft wareand human (users, administrators and management) resources. Their complexitycomes not only from involved technical and organizational structures but mainly fromcomplexity of information processes that must be implemented in specific operationalenvironment (data processing, monitoring, management, etc.). In such a case traditionalmethods of reliability evaluation focused mainly on technical levels are insufficient andmore innovative, multidisciplinary methods of dependability analysis must be applied.Selection of submissions for these proceedings exemplify diversity of topics that mustbe included in such analyses: tools, methodologies and standards for modelling,design and simulation of the systems, security and confidentiality in informationprocessing, specific issues of heterogeneous, today often wireless, computer networks,or management of transportation networks. In addition, this edition of the conferencehosted the 5th CrISS-DESSERT Workshop devoted to the problems of security andsafety in critical information systems.

Popular FPGA Device Families in Implementation of Cryptographic Algorithms

This work evaluates implementation efficiency of different cryptographic algorithms in selected hardware organizations and in different FPGA devices. The tests included AES symmetric cipher and two more contemporary hash algorithms: Salsa20 and Keccak-f[400] permutation function. Each algorithm was realized in hardware in five organizations: the basic iterative one, two with the loop unrolled and two with the loop unrolled and pipelined, then automatically implemented in two popular-grade FPGA devices from Xilinx: Spartan-3 and Spartan-6. Results of 30 test cases allowed for evaluation of particular strengths and weaknesses of the ciphers, the organizations and the FPGA architectures. In particular, the evaluation took into account implementation efficiency offered by the two device families, scalability of the ciphers with the loop unrolling factor and specific routing problems which came out in some configurations.

Low Cost FPGA Devices in High Speed Implementations of Keccak-f Hash Algorithm

Cryptographic hash functions are important components in many applications of contemporary information systems like computation of digital signatures, authentication codes or fingerprinting. The recent SHA-3 competition announced by NIST resulted in developments of new hash methods from which the Keccak algorithm has been selected as the winner after intensive public evaluation of the candidates. In this paper we are discussing various high-speed organizations of the Keccak-f[1600] permutation function – the core component of the Keccak SHA-3 algorithm – which can be created from the basic iterative architecture by round replication (loop unrolling) and pipelining. Different variants of the proposed architectures are implemented in a popular Spartan-3 device form Xilinx and the presented results identify main problems which arise if a high speed architecture of the function is automatically implemented in an FPGA device.

Proceedings of the Ninth International Conference on Dependability and Complex Systems DepCoS-RELCOMEX. June 30 – July 4, 2014, Brunów, Poland

Writing real world distributed applications is a challenging task. Even if well known models or powerful frameworks such as MapReduce or HADOOP are employed, the complexity of the aspects involved, such as specific programming and data models, deployment scripts or a hard debugging process are enough to require many working hours or even make the entire process unsuitable for practical purposes. For applications which need some of their own components to be computed in a distributed manner, a generic model incurs an unnecessary overhead and makes the whole development slower. We propose a MapReduce framework which automatically handles all the distributed computing tasks such as computing resources abstraction, code deployment, objects serialization, remote invocations and synchronizations with only a minimal coding overhead. With only minimal constructions dependable distributed components can be developed and run on heterogeneous platforms and networks. The presented results confirm the performance of the proposed method.

Implementing Salsa20 vs. AES and Serpent Ciphers in Popular-Grade FPGA Devices

Salsa20 is a 256-bit stream cipher that has been proposed to eSTREAM, ECRYPT Stream Cipher Project, and is considered to be one of the most secure and relatively fastest proposals. This paper discusses hardware implementations of this cipher in two organizations – a fully unrolled, pipelined dataflow path and an iterative loop – in low-cost Field Programmable Gate Arrays, and compares them with equivalent realizations of the AES and Serpent block ciphers. The results demonstrate potential of the algorithm when it is implemented in the specific FPGA environment and evaluate its effectiveness in contemporary popular programmable devices.

Implementing AES and Serpent Ciphers in New Generation of Low-Cost FPGA Devices

New generations of FPGA devices that are being continuously developed provide the designers with extended capabilities and create new options for implementation of contemporary ciphers. This work presents implementations of the two best algorithms of the AES contest – Rijndael and Serpent – in Spartan-6 devices from Xilinx and compares them with equivalent effects that were obtained in architectures of the previous generation. The included results allow for evaluation of implementation cost vs. efficiency in contemporary FPGA chips for these two cryptographic algorithms and also provide some conclusions about how the situation changes with development of new, more powerful programmable architectures.

Dependability Engineering and Complex Systems

These proceedings present the results of the Eleventh International Conference on Dependability and Complex Systems DepCoS-RELCOMEX which took place in a picturesque Brunow Palace in Poland from 27th June to 1st July, 2016. DepCoS-RELCOMEX is a series of international conferences organized annually by Department of Computer Engineering of Wroclaw University of Science and Technology since 2006. The roots of the series go as far back as to the seventies of the previous century the first RELCOMEX conference took place in 1977 and now its main aim is to promote a multi-disciplinary approach to dependability problems in theory and engineering practice of complex systems. Complex systems, nowadays most often computer-based and distributed, are built upon a variety of technical, information, software and human resources. The challenges in their design, analysis and maintenance not only originate from the involved technical and organizational structures but also from the complexity of the information processes that must be efficiently executed in a diverse, often hostile operational environment. Traditional methods of reliability evaluation focused only on technical resources are usually insufficient in this context and more innovative, multidisciplinary methods of dependability analysis must be applied. The diversity of the topics which need to be considered is well illustrated by the selection of the submissions in these proceedings with their subjects ranging from mathematical models and design methodologies through software engineering and data security issues up to practical problems in technical, e.g. transportation, systems