50 research outputs found

    Privacy-Preserving Regular Expression Evaluation on Encrypted Data

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    Motivated by the need to outsource file storage to untrusted clouds while still permitting controlled use of that data by authorized third parties, in this dissertation we present a family of protocols by which a client can evaluate a regular expression on an encrypted file stored at a server (the cloud), once authorized to do so by the file owner. We present a protocol that provably protects the privacy of the regular expression and the file contents from a malicious server and the privacy of the file contents (except for the evaluation result) from an honest-but-curious client. We then extend this protocol in two primary directions. In one direction, we develop a strengthened protocol that enables the client to detect any misbehavior of the server; in particular, the client can verify that the result of its regular-expression evaluation is based on the authentic file stored there by the data owner, and in this sense the file and evaluation result are authenticated to the client. The second direction in which we extend our initial protocol is motivated by the vast adoption of resource-constrained mobile devices, and the fact that our protocols involve relatively intensive client-server interaction and computation on the searching client. We therefore investigate an alternative in which the client (e.g., via her mobile device) can submit her encrypted regular expression to a partially trusted proxy, which then interacts with the server hosting the encrypted data and reports the encrypted evaluation result to the client. Neither the search query nor the result is revealed to an honest-but-curious proxy or malicious server during the process. We demonstrate the practicality of the protocol by prototyping a system to perform regular-expression searches on encrypted emails and evaluate its performance using a real-world email dataset.Doctor of Philosoph

    From security to assurance in the cloud: a survey

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    The cloud computing paradigm has become a mainstream solution for the deployment of business processes and applications. In the public cloud vision, infrastructure, platform, and software services are provisioned to tenants (i.e., customers and service providers) on a pay-as-you-go basis. Cloud tenants can use cloud resources at lower prices, and higher performance and flexibility, than traditional on-premises resources, without having to care about infrastructure management. Still, cloud tenants remain concerned with the cloud's level of service and the nonfunctional properties their applications can count on. In the last few years, the research community has been focusing on the nonfunctional aspects of the cloud paradigm, among which cloud security stands out. Several approaches to security have been described and summarized in general surveys on cloud security techniques. The survey in this article focuses on the interface between cloud security and cloud security assurance. First, we provide an overview of the state of the art on cloud security. Then, we introduce the notion of cloud security assurance and analyze its growing impact on cloud security approaches. Finally, we present some recommendations for the development of next-generation cloud security and assurance solutions

    A security concept for distributed data processing systems

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    Today, the amount of raw data available is abundant. As only a small part of this data is in a form fit for further processing, there is many data left to analyze and process. At the same time, cloud services are ubiquitous and allow even small businesses to perform large tasks of distributed data processing without the significant costs required for a suitable computational infrastructure. However, as more and more users transfer their data into the cloud for processing and storage, concerns about data security arise. An extensive review of data security research in today's cloud solutions confirms these concerns to be justified. The existing strategies for securing one's data are not adequate for many use cases. Therefore, this work proposes a holistic security concept for distributed data processing in the cloud. For the purpose of providing security in heterogeneous cloud environments, it statically analyzes a data flow prior to execution and determines the optimal security measurements. Without imposing strict requirements on the cloud services involved, it can be deployed in a broad range of scenarios. The concept's generic design can be adopted by existing data rocessing tools. An exemplary implementation is provided for the mashup tool FlexMash. Requirements, such as data confidentiality, integrity, access control, and scalability were evaluated to be met.Die heutige Menge an vorhandenen Daten ist enorm. Viele davon müssen zunächst verarbeitet und analysiert werden, da nur ein geringer Teil dieser Daten für die weitere Verarbeitung geeignet ist. Cloud-basierte Dienste sind allgegenwärtig und erlauben es auch kleineren Unternehmen Datenverarbeitung durchzuführen, ohne die Kosten von notwendiger Infrastruktur tragen zu müssen. Mit einer zunehmenden Zahl an Nutzern von Clouds wachsen jedoch auch Bedenken der Sicherheit. Eine ausführliche Durchsicht der aktuellen Forschung zu diesem Thema bestätigt diese Bedenken und existierende Strategien zur Sicherung der eigenen Daten berücksichtigen viele Fälle nicht. Daher stellt diese Arbeit ein ganzheitliches Sicherheitskonzept für die verteilte Datenverarbeitung in der Cloud vor. Damit Sicherheit in heterogenen Cloudumgebungen gewährleistet werden kann, wird ein Datenfluss vor der Ausführung statisch analysiert und es werden die für diesen Fluss optimalen Sicherheitsmaßnahmen festgelegt. Das Konzept besitzt einen breiten Anwendungsbereich, da keine straffen Anforderungen an die genutzten Dienste gestellt werden. Das generische Design des Konzepts ermöglicht eine einfache Integration in bereits existierende Datenverarbeitungsanwendungen, wie beispielhaft an FlexMash gezeigt wird. Anforderungen, wie die Vertraulichkeit von Daten, deren Integrität, Zugriffskontrolle und Skalierbarkeit des Systems konnten erreicht werden

    Privacy-preserving machine learning on Apache Spark

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    The adoption of third-party machine learning (ML) cloud services is highly dependent on the security guarantees and the performance penalty they incur on workloads for model training and inference. This paper explores security/performance trade-offs for the distributed Apache Spark framework and its ML library. Concretely, we build upon a key insight: in specific deployment settings, one can reveal carefully chosen non-sensitive operations (e.g. statistical calculations). This allows us to considerably improve the performance of privacy-preserving solutions without exposing the protocol to pervasive ML attacks. In more detail, we propose Soteria, a system for distributed privacy-preserving ML that leverages Trusted Execution Environments (e.g. Intel SGX) to run computations over sensitive information in isolated containers (enclaves). Unlike previous work, where all ML-related computation is performed at trusted enclaves, we introduce a hybrid scheme, combining computation done inside and outside these enclaves. The experimental evaluation validates that our approach reduces the runtime of ML algorithms by up to 41% when compared to previous related work. Our protocol is accompanied by a security proof and a discussion regarding resilience against a wide spectrum of ML attacks.This work was supported by FCT - Portuguese Foundation for Science and Technology through the Ph.D. grant DFA/BD/146528/2018 and realized within the scope of the project LA/P/0063/2020

    Secure data storage and retrieval in cloud computing

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    Nowadays cloud computing has been widely recognised as one of the most inuential information technologies because of its unprecedented advantages. In spite of its widely recognised social and economic benefits, in cloud computing customers lose the direct control of their data and completely rely on the cloud to manage their data and computation, which raises significant security and privacy concerns and is one of the major barriers to the adoption of public cloud by many organisations and individuals. Therefore, it is desirable to apply practical security approaches to address the security risks for the wide adoption of cloud computing

    Analysis of technical implementations of security processes for cloud computing services

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    Створення автоматизованої системи аналізу журналів для виявлення аномалій і загроз безпеки в комп'ютерній системі // Кваліфікаційна робота ОР «Бакалавр» //Микитюк Тарас Володимирович// Тернопільський національний технічний університет імені Івана Пулюя, факультет комп’ютерно-інформаційних систем і програмної інженерії, кафедра кібербезпеки, група СБ-41 // Тернопіль, 2023 // С. – 52, рис. – 25, ліст. – 3.Парадигма хмарних обчислень стала основним рішенням для розгортання бізнес-процесів і програм. У загальнодоступному хмарному баченні послуги інфраструктури, платформи та програмного забезпечення надаються споживачам (тобто клієнтам і постачальникам послуг) на основі оплати за використання. Орендарі хмари можуть використовувати хмарні ресурси за нижчими цінами, з вищою продуктивністю та гнучкістю, ніж традиційні локальні ресурси, не турбуючись про керування інфраструктурою. Тим не менш, орендарі хмари залишаються стурбовані рівнем обслуговування хмари та нефункціональними властивостями, на які можуть розраховувати їхні програми. В останні кілька років дослідницьке співтовариство зосередилося на нефункціональних аспектах парадигми хмари, серед яких виділяється безпека хмари. Дослідження в цій роботі зосереджено на інтерфейсі між безпекою в хмарі та процесами забезпеченням безпеки в хмарі. По-перше, пропонується огляд рівня безпеки в хмарі. Потім подано поняття забезпечення безпеки хмари та аналіз його зростаючого впливу. В роботі наведено ряд рекомендацій стосовно безпеки при використанні хмарних обчислень.The cloud computing paradigm has become the primary solution for deploying business processes and applications. In the public cloud vision, infrastructure, platform, and software services are provided to tenants (i.e., customers and service providers) on a actually utilized services fee basis. Cloud clients can use cloud resources at lower prices, with higher performance and flexibility than traditional on-premises resources. They do not worry about infrastructure management. However, cloud tenants remain concerned about cloud service levels and the non-functional features their applications can expect. Recent few years, the major researches was focused on the non-functional aspects of the cloud computing paradigm, with cloud security standing out. The research in this paper focuses on the interface between cloud security and cloud security processes. First, we provide an overview of the current state of cloud security. We then introduce the concept of cloud security and analyze its growing impact. The work gives a number of recommendations regarding security when using cloud computing for development.ВСТУП ... 7 РОЗДІЛ 1. АНАІЗ ПРОБЛЕМИ ФОРМУВАННЯ ВИМОГ В РОЗПОДІЛЕНИХ КОМАНДАХ ... 9 1.1 Критерії відбору ... 9 1.2 Виділення характеристик безпеки хмарних обчислень ... 10 1.3 Висновки до розділу ... 12 РОЗДІЛ 2. АНАЛІЗ ПУБЛІКАЦІЙ ВІДПОВІДНО ДО КЛАСИФІКАЦІЇ ... 13 2.1 Вразливості, загрози та атаки ... 13 2.1.1 Рівень програми ... 13 2.1.2 Рівень клієнт-клієнт ... 14 2.1.3 Рівень провайдер-клієнт та клієнт-провайдер ... 15 2.2 Безпека хмарних сервісів ... 16 2.2.1 Шифрування ... 17 2.2.2 Сигнатури ... 20 2.2.3 Управління доступом ... 21 2.2.4 Аутентифікація ... 23 2.2.5 Довірені обчислення ... 23 2.2.6 IDS/IPS ... 24 2.2.7 Узагальнення огляду методик забезпечення безпеки в хмарі ... 27 2.3 Забезпечення безпеки ... 27 2.3.1 Тестування ... 30 2.3.2 Моніторинг ... 30 2.3.3 Атестація ... 31 2.3.4 Хмарний аудит/відповідність ... 32 2.3.5 Угода про рівень обслуговування (SLA) ... 33 2.3.6 Узагальнення методів гарантування безпеки ... 34 2.4 Узагальнення результатів огляду літературних джерел ... 34 РОЗДІЛ 3. БЕЗПЕКА ЖИТТЄДІЯЛЬНОСТІ, ОСНОВИ ОХОРОНИ ПРАЦІ ... 41 3.1 Охорона праці та її актуальність в ІТ-сфері ... 41 3.2 Шкідлива дія шуту та вібрації і захист від неї ... 45 ВИСНОВОК ... 51 ПЕРЕЛІК ПОСИЛАНЬ ... 5

    Seamless Communication for Crises Management

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    SECRICOM is proposed as a collaborative research project aiming at development of a reference security platform for EU crisis management operations with two essential ambitions: (A) Solve or mitigate problems of contemporary crisis communication infrastructures (Tetra, GSM, Citizen Band, IP) such as poor interoperability of specialized communication means, vulnerability against tapping and misuse, lack of possibilities to recover from failures, inability to use alternative data carrier and high deployment and operational costs. (B) Add new smart functions to existing services which will make the communication more effective and helpful for users. Smart functions will be provided by distributed IT systems based on an agents’ infrastructure. Achieving these two project ambitions will allow creating a pervasive and trusted communication infrastructure fulfilling requirements of crisis management users and ready for immediate application

    On the evolution of digital evidence: novel approaches for cyber investigation

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    2012-2013Nowadays Internet is the fulcrum of our world, and the World Wide Web is the key to access it. We develop relationships on social networks and entrust sensitive documents to online services. Desktop applications are being replaced by fully-fledged web-applications that can be accessed from any devices. This is possible thanks to new web technologies that are being introduced at a very fast pace. However, these advances come at a price. Today, the web is the principal means used by cyber-criminals to perform attacks against people and organizations. In a context where information is extremely dynamic and volatile, the fight against cyber-crime is becoming more and more difficult. This work is divided in two main parts, both aimed at fueling research against cybercrimes. The first part is more focused on a forensic perspective and exposes serious limitations of current investigation approaches when dealing with modern digital information. In particular, it shows how it is possible to leverage common Internet services in order to forge digital evidence, which can be exploited by a cyber-criminal to claim an alibi. Hereinafter, a novel technique to track cyber-criminal activities on the Internet is proposed, aimed at the acquisition and analysis of information from highly dynamic services such as online social networks. The second part is more concerned about the investigation of criminal activities on the web. Aiming at raising awareness for upcoming threats, novel techniques for the obfuscation of web-based attacks are presented. These attacks leverage the same cuttingedge technology used nowadays to build pleasant and fully-featured web applications. Finally, a comprehensive study of today’s top menaces on the web, namely exploit kits, is presented. The result of this study has been the design of new techniques and tools that can be employed by modern honeyclients to better identify and analyze these menaces in the wild. [edited by author]XII n.s
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