Biblio

The concept of digital right management (DRM) has become extremely important in current mobile environments. This paper shows how partial bitstream encryption can allow the secure distribution of hardware applications resembling the mechanisms of traditional software DRM. Building on the recent developments towards the secure distribution of hardware cores, the paper demonstrates a prototypical implementation of a user mobile device supporting such distribution mechanisms. The prototype extends the Android operating system with support for hardware reconfigurability and showcases the interplay of novel security concepts enabled by hardware DRM, the advantages of a design flow based on high-level synthesis, and the opportunities provided by current software-rich reconfigurable Systems-on-Chips. Relying on this prototype, we also collected extensive quantitative results demonstrating the limited overhead incurred by the secure distribution architecture.

This paper introduces combined data integrity and availability attacks to expand the attack scenarios against power system state estimation. The goal of the adversary, who uses the combined attack, is to perturb the state estimates while remaining hidden from the observer. We propose security metrics that quantify vulnerability of power grids to combined data attacks under single and multi-path routing communication models. In order to evaluate the proposed security metrics, we formulate them as mixed integer linear programming (MILP) problems. The relation between the security metrics of combined data attacks and pure data integrity attacks is analyzed, based on which we show that, when data availability and data integrity attacks have the same cost, the two metrics coincide. When data availability attacks have a lower cost than data integrity attacks, we show that a combined data attack could be executed with less attack resources compared to pure data integrity attacks. Furthermore, it is shown that combined data attacks would bypass integrity-focused mitigation schemes. These conclusions are supported by the results obtained on a power system model with and without a communication model with single or multi-path routing.

Physical consequences to power systems of false data injection cyber-attacks are considered. Prior work has shown that the worst-case consequences of such an attack can be determined using a bi-level optimization problem, wherein an attack is chosen to maximize the physical power flow on a target line subsequent to re-dispatch. This problem can be solved as a mixed-integer linear program, but it is difficult to scale to large systems due to numerical challenges. Three new computationally efficient algorithms to solve this problem are presented. These algorithms provide lower and upper bounds on the system vulnerability measured as the maximum power flow subsequent to an attack. Using these techniques, vulnerability assessments are conducted for IEEE 118-bus system and Polish system with 2383 buses.

This paper presents the analysis and the design of a ferrite permanent magnet synchronous generator (FePMSG) with flux concentration. Despite the well-known advantages of rare earth permanent magnet synchronous generators (REPMSG), the high cost of the rare earth permanent magnets represents an important drawback, particularly in competitive markets like the wind power. To reduce the cost of permanent magnet machines it is possible to replace the expensive rare earth materials by ferrite. Once ferrite has low remanent magnetization, flux concentration techniques are used to design a cheaper generator. The designed FePMSG is compared with a reference rare earth (NdFeB) permanent magnet synchronous generator (REPMSG), both with 3 kW, 220 V and 350 rpm. The results, validated with finite element analysis, show that the FePMSG can replace the REPMSG reducing significantly the active material cost.

The landscape of automotive in-vehicle networks is changing driven by the vast options for infotainment features and progress toward fully-autonomous vehicles. However, the security of automotive networks is lagging behind feature-driven technologies, and new vulnerabilities are constantly being discovered. In this paper, we introduce a road map towards a security solution for in-vehicle networks that can detect anomalous and failed states of the network and adaptively respond in real-time to maintain a fail-operational system.

Learning and remembering how to use APIs is difficult. While code-completion tools can recommend API methods, browsing a long list of API method names and their documentation is tedious. Moreover, users can easily be overwhelmed with too much information. We present a novel API recommendation approach that taps into the predictive power of repetitive code changes to provide relevant API recommendations for developers. Our approach and tool, APIREC, is based on statistical learning from fine-grained code changes and from the context in which those changes were made. Our empirical evaluation shows that APIREC correctly recommends an API call in the first position 59% of the time, and it recommends the correct API call in the top five positions 77% of the time. This is a significant improvement over the state-of-the-art approaches by 30-160% for top-1 accuracy, and 10-30% for top-5 accuracy, respectively. Our result shows that APIREC performs well even with a one-time, minimal training dataset of 50 publicly available projects.

In the modern-day development, projects use Continuous Integration Services (CISs) to execute the build for every change in the source code. To ensure that the project remains correct and deployable, a CIS performs a clean build each time. In a clean environment, a build system needs to retrieve the project's dependencies (e.g., guava.jar). The retrieval, however, can be costly due to dependency bloat: despite a project using only a few files from each library, the existing build systems still eagerly retrieve all the libraries at the beginning of the build. This paper presents a novel build system, Molly, which lazily retrieves parts of libraries (i.e., files) that are needed during the execution of a build target. For example, the compilation target needs only public interfaces of classes within the libraries and the test target needs only implementation of the classes that are being invoked by the tests. Additionally, Molly generates a transfer script that retrieves parts of libraries based on prior builds. Molly's design requires that we ignore the boundaries set by the library developers and look at the files within the libraries. We implemented Molly for Java and evaluated it on 17 popular open-source projects. We show that test targets (on average) depend on only 9.97% of files in libraries. A variant of Molly speeds up retrieval by 44.28%. Furthermore, the scripts generated by Molly retrieve dependencies, on average, 93.81% faster than the Maven build system.

A biometric technology is an emerging field of information technology which can be used to identifying identity of unknown individual based on some characteristics derived from specific physiological and/or behavioral characteristics that the individual possesses. Thus, among several biometric characteristics, which can be derived from the hand, palmprint has been effectively used to improve identification for last years. So far, majority of research works on this biometric trait are fundamentally based on a gray-scale image which acquired using a visible light. Recently, multispectral imaging technology has been used to make the biometric system more efficient. In this work, in order to increase the discriminating ability and the classification system accuracy, we propose a multimodal system which each spectral band of palmprint operates separately and their results are fused at matching score level. In our study, each spectral band is represented by features extracted by PCANet deep learning technique. The proposed scheme is validated using the available CASIA multispectral palmprint database of 100 users. The obtained results showed that the proposed method is very efficient, which can be improved the accuracy rate.

Systems-on-a-Chip are among the best-performing and complete solutions for complex electronic systems. This is also true in the field of network security, an application requiring high performance with low resource usage. This work presents an Advanced Encryption Standard implementation for Systems-on-a-Chip using as a reference the Cipher Block Chaining mode. In particular, a flexible interface based and the Advanced Peripheral Bus to integrate the encryption algorithm with any kind of processor is presented. The hardware-software approach of the architecture is also analyzed and described. The final system was integrated on a Xilinx Zynq 7000 to prototype and evaluate the idea. Results show that our solution demonstrates good performance and flexibility with low resource usage, occupying less than 2% of the Zynq 7000 with a throughput of 320 Mbps. The architecture is suitable when implementations of symmetric encryption algorithms for modern Systems-on-a-Chip are required.

Coming days are becoming a much challenging task for the power system researchers due to the anomalous increase in the load demand with the existing system. As a result there exists a discordant between the transmission and generation framework which is severely pressurizing the power utilities. In this paper a quick and efficient methodology has been proposed to identify the most sensitive or susceptible regions in any power system network. The technique used in this paper comprises of correlation of a multi-bus power system network to an equivalent two-bus network along with the application of Artificial neural network(ANN) Architecture with training algorithm for online monitoring of voltage security of the system under all multiple exigencies which makes it more flexible. A fast voltage stability indicator has been proposed known as Unified Voltage Stability Indicator (UVSI) which is used as a substratal apparatus for the assessment of the voltage collapse point in a IEEE 30-bus power system in combination with the Feed Forward Neural Network (FFNN) to establish the accuracy of the status of the system for different contingency configurations.

Separation of network control from devices in Software Defined Network (SDN) allows for centralized implementation and management of security policies in a cloud computing environment. The ease of programmability also makes SDN a great platform implementation of various initiatives that involve application deployment, dynamic topology changes, and decentralized network management in a multi-tenant data center environment. Dynamic change of network topology, or host reconfiguration in such networks might require corresponding changes to the flow rules in the SDN based cloud environment. Verifying adherence of these new flow policies in the environment to the organizational security policies and ensuring a conflict free environment is especially challenging. In this paper, we extend the work on rule conflicts from a traditional environment to an SDN environment, introducing a new classification to describe conflicts stemming from cross-layer conflicts. Our framework ensures that in any SDN based cloud, flow rules do not have conflicts at any layer; thereby ensuring that changes to the environment do not lead to unintended consequences. We demonstrate the correctness, feasibility and scalability of our framework through a proof-of-concept prototype.

Online Social Networks (OSNs) are continuously suffering from the negative impact of Cross-Site Scripting (XSS) vulnerabilities. This paper describes a novel framework for mitigating XSS attack on OSN-based platforms. It is completely based on the request authentication and view isolation approach. It detects XSS attack through validating string value extracted from the vulnerable checkpoint present in the web page by implementing string examination algorithm with the help of XSS attack vector repository. Any similarity (i.e. string is not validated) indicates the presence of malicious code injected by the attacker and finally it removes the script code to mitigate XSS attack. To assess the defending ability of our designed model, we have tested it on OSN-based web application i.e. Humhub. The experimental results revealed that our model discovers the XSS attack vectors with low false negatives and false positive rate tolerable performance overhead.

In this work, we give a lattice attack on the ECDSA implementation in the latest version of OpenSSL, which implement the scalar multiplication by windowed Non-Adjacent Form method. We propose a totally different but more efficient method of extracting and utilizing information from the side-channel results, remarkably improving the previous attacks. First, we develop a new efficient method, which can extract almost all information from the side-channel results, obtaining 105.8 bits of information per signature on average for 256-bit ECDSA. Then in order to make the utmost of our extracted information, we translate the problem of recovering secret key to the Extended Hidden Number Problem, which can be solved by lattice reduction algorithms. Finally, we introduce the methods of elimination, merging, most significant digit recovering and enumeration to improve the attack. Our attack is mounted to the \series secp256k1\ curve, and the result shows that only 4 signatures would be enough to recover the secret key if the Flush+Reload attack is implemented perfectly without any error,which is much better than the best known result needing at least 13 signatures.

Defending computer networks from ongoing security incidents is a key requirement to ensure service continuity. Handling incidents in real-time is a complex process consisting of the three single steps: intrusion detection, alert processing and intrusion response. For useful and automated incident handling a comprehensive view on the process and tightly interleaved single steps are required. Existing solutions for incident handling merely focus on a single step leaving the other steps completely aside. Incompatible and encapsulated partial solutions are the consequence. This paper proposes an incident handling systems (IHS) based on a novel execution model that allows interleaving and collaborative interaction between the incident handling steps realized using the Blackboard Pattern. Our holistic information model lays the foundation for a conflict-free collaboration. The incident handling steps are further segmented into exchangeable functional blocks distributed across the network. To show the applicability of our approach, typical use cases for incident handling systems are identified and tested with our implementation.

While both radio and visible light waves can serve as the transmission medium, the propagation channel plays a key role in the highly dynamic vehicular communication environment. We discuss salient properties of radio and visible light channels, including radiation pattern and path loss modeling. By comparing their similarities and highlighting the differences, we illustrate the unique capabilities and limitations of these two technologies with respect to the requirements of Cooperative Intelligent Transportation System applications.

Content Security Policy (CSP) is an emerging W3C standard introduced to mitigate the impact of content injection vulnerabilities on websites. We perform a systematic, large-scale analysis of four key aspects that impact on the effectiveness of CSP: browser support, website adoption, correct configuration and constant maintenance. While browser support is largely satisfactory, with the exception of few notable issues, our analysis unveils several shortcomings relative to the other three aspects. CSP appears to have a rather limited deployment as yet and, more crucially, existing policies exhibit a number of weaknesses and misconfiguration errors. Moreover, content security policies are not regularly updated to ban insecure practices and remove unintended security violations. We argue that many of these problems can be fixed by better exploiting the monitoring facilities of CSP, while other issues deserve additional research, being more rooted into the CSP design.

Differential privacy is a precise mathematical constraint meant to ensure privacy of individual pieces of information in a database even while queries are being answered about the aggregate. Intuitively, one must come to terms with what differential privacy does and does not guarantee. For example, the definition prevents a strong adversary who knows all but one entry in the database from further inferring about the last one. This strong adversary assumption can be overlooked, resulting in misinterpretation of the privacy guarantee of differential privacy. Herein we give an equivalent definition of privacy using mutual information that makes plain some of the subtleties of differential privacy. The mutual-information differential privacy is in fact sandwiched between ε-differential privacy and (ε,δ)-differential privacy in terms of its strength. In contrast to previous works using unconditional mutual information, differential privacy is fundamentally related to conditional mutual information, accompanied by a maximization over the database distribution. The conceptual advantage of using mutual information, aside from yielding a simpler and more intuitive definition of differential privacy, is that its properties are well understood. Several properties of differential privacy are easily verified for the mutual information alternative, such as composition theorems.

In this paper we describe a system that allows the real time creation of firewall rules in response to geographic and political changes in the control-plane. This allows an organization to mitigate data exfiltration threats by analyzing Border Gateway Protocol (BGP) updates and blocking packets from being routed through problematic jurisdictions. By inspecting the autonomous system paths and referencing external data sources about the autonomous systems, a BGP participant can infer the countries that traffic to a particular destination address will traverse. Based on this information, an organization can then define constraints on its egress traffic to prevent sensitive data from being sent via an untrusted region. In light of the many route leaks and BGP hijacks that occur today, this offers a new option to organizations willing to accept reduced availability over the risk to confidentiality. Similar to firewalls that allow organizations to block traffic originating from specific countries, our approach allows blocking outbound traffic from transiting specific jurisdictions. To illustrate the efficacy of this approach, we provide an analysis of paths to various financial services IP addresses over the course of a month from a single BGP vantage point that quantifies the frequency of path alterations resulting in the traversal of new countries. We conclude with an argument for the utility of country-based egress policies that do not require the cooperation of upstream providers.

Device-free localization of people and objects indoors not equipped with radios is playing a critical role in many emerging applications. This paper presents a novel channel state information (CSI) pre-processing scheme that enables accurate device-free localization indoors. The basic idea is simple: CSI is sensitive to a target's location and by modelling the CSI measurements of multiple wireless links as a set of power fading based equations, the target location can be determined. However, due to rich multipaths in indoor environment, the received signal strength (RSS) or even the fine-grained CSI can not be easily modelled. We observe that even in a rich multipath environment, not all subcarriers are equally affected by multipath reflections. Our preprocessing scheme tries to identify the subcarriers not affected by multipath. Thus, CSIs on the "clean" subcarriers can be modelled and utilized for accurate localization. Extensive experiments demonstrate the effectiveness of the proposed pre-processing scheme.

Poor data quality has become a persistent challenge for organizations as data continues to grow in complexity and size. Existing data cleaning solutions focus on identifying repairs to the data to minimize either a cost function or the number of updates. These techniques, however, fail to consider underlying data privacy requirements that exist in many real data sets containing sensitive and personal information. In this demonstration, we present PARC, a Privacy-AwaRe data Cleaning system that corrects data inconsistencies w.r.t. a set of FDs, and limits the disclosure of sensitive values during the cleaning process. The system core contains modules that evaluate three key metrics during the repair search, and solves a multi-objective optimization problem to identify repairs that balance the privacy vs. utility tradeoff. This demonstration will enable users to understand: (1) the characteristics of a privacy-preserving data repair; (2) how to customize data cleaning and data privacy requirements using two real datasets; and (3) the distinctions among the repair recommendations via visualization summaries.

Recently there has been much interest in performing search queries over encrypted data to enable functionality while protecting sensitive data. One particularly efficient mechanism for executing such queries is order-preserving encryption/encoding (OPE) which results in ciphertexts that preserve the relative order of the underlying plaintexts thus allowing range and comparison queries to be performed directly on ciphertexts. Recently, Popa et al. (SP 2013) gave the first construction of an ideally-secure OPE scheme and Kerschbaum (CCS 2015) showed how to achieve the even stronger notion of frequency-hiding OPE. However, as Naveed et al. (CCS 2015) have recently demonstrated, these constructions remain vulnerable to several attacks. Additionally, all previous ideal OPE schemes (with or without frequency-hiding) either require a large round complexity of O(log n) rounds for each insertion, or a large persistent client storage of size O(n), where n is the number of items in the database. It is thus desirable to achieve a range query scheme addressing both issues gracefully. In this paper, we propose an alternative approach to range queries over encrypted data that is optimized to support insert-heavy workloads as are common in "big data" applications while still maintaining search functionality and achieving stronger security. Specifically, we propose a new primitive called partial order preserving encoding (POPE) that achieves ideal OPE security with frequency hiding and also leaves a sizable fraction of the data pairwise incomparable. Using only O(1) persistent and O(ne) non-persistent client storage for 0(1-e)) search queries. This improved security and performance makes our scheme better suited for today's insert-heavy databases.