Biblio

This paper deals with the modeling and control of the NEREIDA wave generation power plant installed in Mutriku, Spain. This kind of Oscillating Water Column (OWC) plants usually employ a Wells turbine coupled to a Doubly Fed Induction Generator (DFIG). The stalling behavior of the Wells turbine limits the generated power. In this context, a sliding mode rotational speed control is proposed to help avoiding this phenomenon. This will regulate the speed by means of the Rotor Side Converter (RSC) of the Back-to-Back converter governing the generator. The results of the comparative study show that the proposed control provides a higher generated power compared to the uncontrolled case.

Problem: Today, many methods of influencing on personnel in the communication process are available to social engineers and information security specialists, but in practice it is difficult to say which method and why it is appropriate to use one. Criteria and indicators of effective communication are not formalized. Purpose: to formalize the concept of effective communication, to offer a tool for combining existing methods and means of communication, to formalize the purpose of communication. Methods: Use of the terminal model of a control system for a non-stochastic communication object. Results. Two examples demonstrating the possibility of using the terminal model of the communication control system, which allows you to connect tools and methods of communication, justify the requirements for the structure and feedback of communication, select the necessary communication algorithms depending on the observed response of the communication object. Practical significance: the results of the research can be used in planning and conducting effective communication in the process of information protection, in business, in private relationships and in other areas of human activity.

Security-sensitive workflows impose constraints on the control-flow and authorization policies that may lead to unsatisfiable instances. In these cases, it is still possible to find "least bad" executions where costs associated to authorization violations are minimized, solving the so-called Multi-Objective Workflow Satisfiability Problem (MO-WSP). The MO-WSP is inspired by the Valued WSP and its generalization, the Bi-Objective WSP, but our work considers quantitative solutions to the WSP without abstracting control-flow constraints. In this paper, we define variations of the MO-WSP and solve them using bounded model checking and optimization modulo theories solving. We validate our solutions on real-world workflows and show their scalability on synthetic instances.

Scheduling in the cloud is a complex task due to the number and variety of resources available and the volatility of usage-patterns of resources considering that the resource setting is on the service provider. This complexity is compounded further when Security issues and Quality of Service (QoS) are also factored in. The aim of this paper is to describe a model that based on Security (SSM) as a key element that cloud services rely on which affects the performance, cost and time concerns within the security constraints of the cloud service. Definition of the Scheduling Security Model (SSM), and evaluation through worked example that can meet the customer requirements of cost and the quality of service in the required time.

For the past decade, security experts have warned that malicious engineers could modify hardware designs to include hardware backdoors (trojans), which, in turn, could grant attackers full control over a system. Proposed defenses to detect these attacks have been outpaced by the development of increasingly small, but equally dangerous, trojans. To thwart trojan-based attacks, we propose a novel architecture that maps the security-critical portions of a processor design to a one-time programmable, LUT-free fabric. The programmable fabric is automatically generated by analyzing the HDL of targeted modules. We present our tools to generate the fabric and map functionally equivalent designs onto the fabric. By having a trusted party randomly select a mapping and configure each chip, we prevent an attacker from knowing the physical location of targeted signals at manufacturing time. In addition, we provide decoy options (canaries) for the mapping of security-critical signals, such that hardware trojans hitting a decoy are thwarted and exposed. Using this defense approach, any trojan capable of analyzing the entire configurable fabric must employ complex logic functions with a large silicon footprint, thus exposing it to detection by inspection. We evaluated our solution on a RISC-V BOOM processor and demonstrated that, by providing the ability to map each critical signal to 6 distinct locations on the chip, we can reduce the chance of attack success by an undetectable trojan by 99%, incurring only a 27% area overhead.

Symbolic methods have been used extensively for proving security of cryptographic protocols in the Dolev-Yao model, and more recently for proving security of cryptographic primitives and constructions in the computational model. However, existing methods for proving security of cryptographic constructions in the computational model often require significant expertise and interaction, or are fairly limited in scope and expressivity. This paper introduces a symbolic approach for proving security of cryptographic constructions based on the Learning With Errors assumption (Regev, STOC 2005). Such constructions are instances of lattice-based cryptography and are extremely important due to their potential role in post-quantum cryptography. Following (Barthe, Grégoire and Schmidt, CCS 2015), our approach combines a computational logic and deducibility problems—a standard tool for representing the adversary's knowledge, the Dolev-Yao model. The computational logic is used to capture (indistinguishability-based) security notions and drive the security proofs whereas deducibility problems are used as side-conditions to control that rules of the logic are applied correctly. We then use AutoLWE, an implementation of the logic, to deliver very short or even automatic proofs of several emblematic constructions, including CPA-PKE (Gentry et al., STOC 2008), (Hierarchical) Identity-Based Encryption (Agrawal et al. Eurocrypt 2010), Inner Product Encryption (Agrawal et al. Asiacrypt 2011), CCA-PKE (Micciancio et al., Eurocrypt 2012). The main technical novelty beyond AutoLWE is a set of (semi-)decision procedures for deducibility problems, using extensions of Gröbner basis computations for subalgebras in the (non-)commutative setting (instead of ideals in the commutative setting). Our procedures cover the theory of matrices, which is required for lattice-based assumption, as well as the theory of non-commutative rings, fields, and Diffie-Hellman exponentiation, in its standard, bilinear and multilinear forms. Additionally, AutoLWE supports oracle-relative assumptions, which are used specifically to apply (advanced forms of) the Leftover Hash Lemma, an information-theoretical tool widely used in lattice-based proofs.

Developers commonly use fuzzing techniques to hunt down all manner of memory corruption vulnerabilities during the testing phase. Irrespective of the fuzzer, input mutation plays a central role in providing adequate code coverage, as well as in triggering bugs. However, each class of memory corruption bugs requires a different trigger condition. While the goal of a fuzzer is to find bugs, most existing fuzzers merely approximate this goal by targeting their mutation strategies toward maximizing code coverage. In this work, we present a new mutation strategy that maximizes the likelihood of triggering memory-corruption bugs by generating fewer, but better inputs. In particular, our strategy achieves bug-directed mutation by inferring the type of the input bytes. To do so, it tags each offset of the input with a basic type (e.g., 32-bit integer, string, array etc.), while deriving mutation rules for specific classes of bugs. We infer types by means of in-memory data-structure identification and dynamic taint analysis, and implement our novel mutation strategy in a fully functional fuzzer which we call TIFF (Type Inference-based Fuzzing Framework). Our evaluation on real-world applications shows that type-based fuzzing triggers bugs much earlier than existing solutions, while maintaining high code coverage. For example, on several real-world applications and libraries (e.g., poppler, mpg123 etc.), we find real bugs (with known CVEs) in almost half of the time and upto an order of magnitude fewer inputs than state-of-the-art fuzzers.

5G is envisioned as a transformation of the communications architecture towards multi-tenant, scalable and flexible infrastructure, which heavily relies on virtualised network functions and programmable networks. In particular, orchestration will advance one step further in blending both compute and data resources, usually dedicated to virtualisation technologies, and network resources into so-called slices. Although 5G security is being developed in current working groups, slice security is seldom addressed. In this work, we propose to integrate security in the slice life cycle, impacting its management and orchestration that relies on the virtualization/softwarisation infrastructure. The proposed security architecture connects the demands specified by the tenants through as-a-service mechanisms with built-in security functions relying on the ability to combine enforcement and monitoring functions within the software-defined network infrastructure. The architecture exhibits desirable properties such as isolating slices down to the hardware resources or monitoring service-level performance.

Insider threats pose a challenge to all companies and organizations. Identification of culprit after an attack is often too late and result in detrimental consequences for the organization. Majority of past research on insider threat has focused on post-hoc personality analysis of known insider threats to identify personality vulnerabilities. It has been proposed that certain personality vulnerabilities place individuals to be at risk to perpetuating insider threats should the environment and opportunity arise. To that end, this study utilizes a game-based approach to simulate a scenario of intellectual property theft and investigate behavioral and personality differences of individuals who exhibit insider-threat related behavior. Features were extracted from games, text collected through implicit and explicit measures, simultaneous facial expression recordings, and personality variables (HEXACO, Dark Triad and Entitlement Attitudes) calculated from questionnaire. We applied ensemble machine learning algorithms and show that they produce an acceptable balance of precision and recall. Our results showcase the possibility of harnessing personality variables, facial expressions and linguistic features in the modeling and prediction of insider-threat.

Human behavior is increasingly sensed and recorded and used to create models that accurately predict the behavior of consumers, employees, and citizens. While behavioral models are important in many domains, the ability to predict individuals' behavior is in the focus of growing privacy concerns. The legal and technological measures for privacy do not adequately recognize and address the ability to infer behavior and traits. In this position paper, we first analyze the shortcoming of existing privacy theories in addressing AI's inferential abilities. We then point to legal and theoretical frameworks that can adequately describe the potential of AI to negatively affect people's privacy. We then present a technical privacy measure that can help bridge the divide between legal and technical thinking with respect to AI and privacy.

Compromised smart meters sending false power consumption data in Advanced Metering Infrastructure (AMI) may have drastic consequences on the smart grid»s operation. Most existing defense models only deal with electricity theft from individual customers (isolated attacks) using supervised classification techniques that do not offer scalable or real time solutions. Furthermore, the cyber and interconnected nature of AMIs can also be exploited by organized adversaries who have the ability to orchestrate simultaneous data falsification attacks after compromising several meters, and also have more complex goals than just electricity theft. In this paper, we first propose a real time semi-supervised anomaly based consensus correction technique that detects the presence and type of smart meter data falsification, and then performs a consensus correction accordingly. Subsequently, we propose a semi-supervised consensus based trust scoring model, that is able to identify the smart meters injecting false data. The main contribution of the proposed approach is to provide a practical framework for compromised smart meter identification that (i) is not supervised (ii) enables quick identification (iii) scales classification error rates better for larger sized AMIs; (iv) counters threats from both isolated and orchestrated attacks; and (v) simultaneously works for a variety of data falsification types. Extensive experimental validation using two real datasets from USA and Ireland, demonstrates the ability of our proposed method to identify compromised meters in near real time across different datasets.

Similar to digital circuits, analog and mixed-signal (AMS) circuits are also susceptible to supply-chain attacks such as piracy, overproduction, and Trojan insertion. However, unlike digital circuits, supply-chain security of AMS circuits is less explored. In this work, we propose to perform "logic locking" on digital section of the AMS circuits. The idea is to make the analog design intentionally suffer from the effects of process variations, which impede the operation of the circuit. Only on applying the correct key, the effect of process variations are mitigated, and the analog circuit performs as desired. We provide the theoretical guarantees of the security of the circuit, and along with simulation results for the band-pass filter, low-noise amplifier, and low-dropout regulator, we also show experimental results of our technique on a band-pass filter.

In rapid continuous software development, time- and cost-effective prototyping techniques are beneficial through enabling software designers to quickly explore and evaluate different design concepts. Regarding low-fidelity prototyping for augmented reality (AR) applications, software designers are so far restricted to non-digital prototypes, which enable the visualization of first design concepts, but can be laborious in capturing interactivity. The lack of empirical values and standards for designing user interactions in AR-software leads to a particular need for applying end-user feedback to software refinement. In this paper we present the concept of a tool for rapid digital prototyping for augmented reality applications, enabling software designers to rapidly design augmented reality prototypes, without requiring programming skills. The prototyping tool focuses on modeling multimodal interactions, especially regarding the interaction with physical objects, as well as performing user-based studies to integrate valuable end-user feedback into the refinement of software aspects.

The Java 8 Stream API sets forth a promising new programming model that incorporates functional-like, MapReduce-style features into a mainstream programming language. However, using streams correctly and efficiently may involve subtle considerations. In this poster, we present our ongoing work and preliminary results towards an automated refactoring approach that assists developers in writing optimal stream code. The approach, based on ordering and typestate analysis, determines when it is safe and advantageous to convert streams to parallel and optimize parallel streams.

With Electricity as a fundamental part of our life, its production has still large, negative environmental impact. Therefore, one strain of research is to optimize electricity usage by avoiding its unnecessary consumption or time its consumption when green energy is available. The shift towards an Advanced Metering Infrastructure (AMI) allows to optimize energy distribution based on the current load at residence level. However, applications such as Demand Management and Advanced Load Forecasting require information further down at device level, which cannot be provided by standard electricity meters nor existing AMIs. Hence, different approaches for appliance monitoring emerged over the past 30 years which are categorized into Intrusive systems requiring multiple distributed sensors and Non-Intrusive systems requiring a single unobtrusive sensor. Although each category has been individually explored, hybrid approaches have received little attention. Our experiments highlight that variable consumer devices (e.g. PCs) are detrimental to the detection performance of non-intrusive systems. We further show that their influence can be inhibited by using sensor data from additional intrusive sensors. Even fairly straightforward sensor fusion techniques lead to a classification performance (F1) gain from 84.88 % to 93.41 % in our test setup. As this highlights the potential to contribute to the global goal of saving energy, we define further research directions for hybrid load monitoring systems.

Decision making in utilities, municipal, and energy companies depends on accurate and trustworthy weather information and predictions. Recently, crowdsourced personal weather stations (PWS) are being increasingly used to provide a higher spatial and temporal resolution of weather measurements. However, tools and methods to ensure the trustworthiness of the crowdsourced data in real-time are lacking. In this paper, we present a Reputation System for Crowdsourced Rainfall Networks (RSCRN) to assign trust scores to personal weather stations in a region. Using real PWS data from the Weather Underground service in the high flood risk region of Norfolk, Virginia, we evaluate the performance of the proposed RSCRN. The proposed method is able to converge to a confident trust score for a PWS within 10–20 observations after installation. Collectively, the results indicate that the trust score derived from the RSCRN can reflect the collective measure of trustworthiness to the PWS, ensuring both useful and trustworthy data for modeling and decision-making in the future.

Nowadays, The incorporation of different function of the network, as well as routing, administration, and security, is basic to the effective operation of a mobile circumstantial network these days, in MANET thought researchers manages the problems of QoS and security severally. Currently, each the aspects of security and QoS influence negatively on the general performance of the network once thought-about in isolation. In fact, it will influence the exceptionally operating of QoS and security algorithms and should influence the important and essential services needed within the MANET. Our paper outlines 2 accomplishments via; the accomplishment of security and accomplishment of quality. The direction towards achieving these accomplishments is to style and implement a protocol to suite answer for policy-based network administration, and methodologies for key administration and causing of IPsec in a very MANET.

Deprecation is a language feature that allows API producers to mark a feature as obsolete. We aim to gain a deep understanding of the needs of API producers and consumers alike regarding deprecation. To that end, we investigate why API producers deprecate features, whether they remove deprecated features, how they expect consumers to react, and what prompts an API consumer to react to deprecation. To achieve this goal we conduct semi-structured interviews with 17 third-party Java API producers and survey 170 Java developers. We observe that the current deprecation mechanism in Java and the proposal to enhance it does not address all the needs of a developer. This leads us to propose and evaluate three further enhancements to the deprecation mechanism.

This article shows the analogy between natural language texts and quantum-like systems on the example of the Bell test calculating. The applicability of the well-known Bell test for texts in Russian is investigated. The possibility of using this test for the text separation on the topics corresponding to the user query in information retrieval system is shown.

In big data environments with big number of users and high volume of data, we need to manage the corresponding huge number of security policies. Due to the distributed management of these policies, they may contain several anomalies, such as conflicts and redundancies, which may lead to both safety and availability problems. The distributed systems guided by such security policies produce a huge number of access logs. Due to potential security breaches, the access logs may show the presence of non-allowed accesses. This may also be a consequence of conflicting rules in the security policies. In this paper, we present an ongoing work on developing an environment for verifying and correcting security policies. To make the approach efficient, an access log is used as input to determine suspicious parts of the policy that should be considered. The approach is also made efficient by clustering the policy and the access log and considering separately the obtained clusters. The clustering technique and the use of access log significantly reduces the complexity of the suggested approach, making it scalable for large amounts of data.

Although virtual reality hardware is now widely available, the uptake of real walking is hindered by the fact that it requires often impractically large amounts of physical space. To address this, we present VirtualSpace, a novel system that allows overloading multiple users immersed in different VR experiences into the same physical space. VirtualSpace accomplishes this by containing each user in a subset of the physical space at all times, which we call tiles; app-invoked maneuvers then shuffle tiles and users across the entire physical space. This allows apps to move their users to where their narrative requires them to be while hiding from users that they are confined to a tile. We show how this enables VirtualSpace to pack four users into 16m2. In our study we found that VirtualSpace allowed participants to use more space and to feel less confined than in a control condition with static, pre-allocated space.

In this paper, we present initial work towards creating an intelligent interface that can act as an open access laboratory for visual stylometry called WAIVS, Workflows for Analysis of Images and Visual Stylometry. WAIVS allows scholars, students, and other interested parties to explore the nature of artistic style using cutting-edge research methods in visual stylometry. We create semantic workflows for this interface using various computer vision algorithms that not only facilitate artistically significant analyses but also impose intelligent semantic constraints on complex analyses. In the interface, we combine these workflows with a manually-curated dataset for analysis of artistic style based on either the school of art or the medium.

As a frequent participant in eSociety, Willeke is often preoccupied with paperwork because there is no easy to use, affordable way to act as a qualified person in the digital world. Confidential interactions take place over insecure channels like e-mail and post. This situation poses risks and costs for service providers, civilians and governments, while goals regarding confidentiality and privacy are not always met. The objective of this paper is to demonstrate an alternative architecture in which identifying persons, exchanging information, authorizing external parties and signing documents will become more user-friendly and secure. As a starting point, each person has their personal data space, provided by a qualified trust service provider that also issues a high level of assurance electronic ID. Three main building blocks are required: (1) secure exchange between the personal data space of each person, (2) coordination functionalities provided by a token based infrastructure, and (3) governance over this infrastructure. Following the design science research approach, we developed prototypes of the building blocks that we will pilot in practice. Policy makers and practitioners that want to enable Willeke to get rid of her paperwork can find guidance throughout this paper and are welcome to join the pilots in the Netherlands.

This paper presents an authentication protocol specifically tailored for IoT devices that inherently limits the number of times that an entity can authenticate itself with a given key pair. The protocol we propose is based on a stateful hash-based digital signature system called eXtended Merkle Signature Scheme (XMSS), which has increased its popularity of late due to its resistance to quantum-computer-aided attacks. We propose a 1-pass authentication protocol that can be customized according to the server capabilities to keep track of the key pair state. In addition, we present results when ported to ARM Cortex-M3 and M0 processors.