Research Philosophy of Modern Cryptography

Proposing novel cryptography schemes (e.g., encryption, signatures, and protocols) is one of the main research goals in modern cryptography. In this paper, based on more than 800 research papers since 1976 that we have surveyed, we introduce the research philosophy of cryptography behind these papers. We use ``benefits and ``novelty as the keywords to introduce the research philosophy of proposing new schemes, assuming that there is already one scheme proposed for a cryptography notion. Next, we introduce how benefits were explored in the literature and we have categorized the methodology into 3 ways for benefits, 6 types of benefits, and 17 benefit areas. As examples, we introduce 40 research strategies within these benefit areas that were invented in the literature. The introduced research strategies have covered most cryptography schemes published in top-tier cryptography conferences

Achieving cybersecurity in blockchain-based systems: a survey

With The Increase In Connectivity, The Popularization Of Cloud Services, And The Rise Of The Internet Of Things (Iot), Decentralized Approaches For Trust Management Are Gaining Momentum. Since Blockchain Technologies Provide A Distributed Ledger, They Are Receiving Massive Attention From The Research Community In Different Application Fields. However, This Technology Does Not Provide With Cybersecurity By Itself. Thus, This Survey Aims To Provide With A Comprehensive Review Of Techniques And Elements That Have Been Proposed To Achieve Cybersecurity In Blockchain-Based Systems. The Analysis Is Intended To Target Area Researchers, Cybersecurity Specialists And Blockchain Developers. For This Purpose, We Analyze 272 Papers From 2013 To 2020 And 128 Industrial Applications. We Summarize The Lessons Learned And Identify Several Matters To Foster Further Research In This AreaThis work has been partially funded by MINECO, Spain grantsTIN2016-79095-C2-2-R (SMOG-DEV) and PID2019-111429RB-C21 (ODIO-COW); by CAM, Spain grants S2013/ICE-3095 (CIBERDINE),P2018/TCS-4566 (CYNAMON), co-funded by European Structural Funds (ESF and FEDER); by UC3M-CAM grant CAVTIONS-CM-UC3M; by the Excellence Program for University Researchers, Spain; and by Consejo Superior de Investigaciones Científicas (CSIC), Spain under the project LINKA20216 (“Advancing in cybersecurity technologies”, i-LINK+ program)

Design and evaluation of blockchain-based security protocols

Many security protocols rely on the assumption that the trusted third party (TTP) will behave “as it should”. However, this assumption is difficult to justify in the real world. A TTP may become malicious due to its hidden interests or having been compromised. It is publicly acknowledged that a failed TTP can easily destroy the entire security protocol. This thesis aims to provide results on how to use blockchain technologies to mitigate TTP challenges and thereby secure existing cryptographic protocols. Firstly, we formally define a smart contract-based TTP (denoted as TTP-I) and give two security protocols based on such a type of TTP as concrete instances. In this approach, a smart contract can either complement a TTP’s actions or take over the entire functions of the existing TTP. This helps to obtain many security properties such as transparency and accountability. Smart contracts, however, are not adequate to replace TTP that is capable of maintaining secret information since all the states changed by TTP-I are in plaintext and publicly accessible. To fill the gap, we propose another type of TTP (denoted as TTP-II) that enables confidential executions by combining smart contracts and Trusted Execution Environments (TEEs). To achieve this goal, we first investigate the state-of-the-art TEE-aided confidential smart contracts and then explore their core mechanisms. We further apply TTP-II to a traceable credential system and an accountable decryption system. These systems are proved secure and feasible. However, since blockchain systems suffer from scalability and performance issues, the development of blockchain-based cryptographic protocols is inevitably retarded. At last, to make better blockchain systems, we provide two core mechanisms: a weak consensus algorithm and a delegatable payment protocol. The weak consensus algorithm allows parallel block generation, improving the performance and scalability of upper-layer blockchain systems. The delegatable payment protocol creates an offline payment channel, improving the payment speed. Both proposed algorithms have been practically implemented and systematically evaluated. Notably, the weak consensus algorithm has already been taken up by industries. Video abstract: https://youtu.be/rkAatxBRau

Development of a Trust-enhanced Data Sharing System

Despite importance of data sharing, there are several challenges yet to be tackled, especially security and privacy in which the users roughly may trust to utilize a platform that is insecure to protect privacy violation. Recently, blockchain technology as an immutable and decentralized ledger has emerged to be a promising solution to security and privacy issues. To improve the trust in data sharing systems, reputation systems are deemed advantageous. In fact, the users receive reputation based on their collaboration. It is worth noting, the blockchain-based data sharing and reputation systems impose complexities to the systems as well. This work presents an improved data sharing scheme in terms of privacy, security and latency. The idea features enhancement in performance of blockchain technology and reputation system. Besides, we have implemented the proposed idea as a web application to provide facilitated access for data sharing users. Most of the challenges of development are originated from the fact that many parts of this implementation is from scratch, unlike most of research works on data sharing implementations. We opted for this type of development because there exist common demerits in developments of data sharing frameworks and we believe the reason is to utilize the external and built-in tools imposing many constraints, e.g. communication costs. Besides, the development steps and their corresponding challenges are demonstrated as well. As the final stage, we evaluated the performance and depicted the results to compare and assess the quality of implemented data sharing framework

A Framework for Facilitating Secure Design and Development of IoT Systems

The term Internet of Things (IoT) describes an ever-growing ecosystem of physical objects or things interconnected with each other and connected to the Internet. IoT devices consist of a wide range of highly heterogeneous inanimate and animate objects. Thus, a thing in the context of the IoT can even mean a person with blood pressure or heart rate monitor implant or a pet with a biochip transponder. IoT devices range from ordinary household appliances, such as smart light bulbs or smart coffee makers, to sophisticated tools for industrial automation. IoT is currently leading a revolutionary change in many industries and, as a result, a lot of industries and organizations are adopting the paradigm to gain a competitive edge. This allows them to boost operational efficiency and optimize system performance through real-time data management, which results in an optimized balance between energy usage and throughput. Another important application area is the Industrial Internet of Things (IIoT), which is the application of the IoT in industrial settings. This is also referred to as the Industrial Internet or Industry 4.0, where Cyber- Physical Systems (CPS) are interconnected using various technologies to achieve wireless control as well as advanced manufacturing and factory automation. IoT applications are becoming increasingly prevalent across many application domains, including smart healthcare, smart cities, smart grids, smart farming, and smart supply chain management. Similarly, IoT is currently transforming the way people live and work, and hence the demand for smart consumer products among people is also increasing steadily. Thus, many big industry giants, as well as startup companies, are competing to dominate the market with their new IoT products and services, and hence unlocking the business value of IoT. Despite its increasing popularity, potential benefits, and proven capabilities, IoT is still in its infancy and fraught with challenges. The technology is faced with many challenges, including connectivity issues, compatibility/interoperability between devices and systems, lack of standardization, management of the huge amounts of data, and lack of tools for forensic investigations. However, the state of insecurity and privacy concerns in the IoT are arguably among the key factors restraining the universal adoption of the technology. Consequently, many recent research studies reveal that there are security and privacy issues associated with the design and implementation of several IoT devices and Smart Applications (smart apps). This can be attributed, partly, to the fact that as some IoT device makers and smart apps development companies (especially the start-ups) reap business value from the huge IoT market, they tend to neglect the importance of security. As a result, many IoT devices and smart apps are created with security vulnerabilities, which have resulted in many IoT related security breaches in recent years. This thesis is focused on addressing the security and privacy challenges that were briefly highlighted in the previous paragraph. Given that the Internet is not a secure environ ment even for the traditional computer systems makes IoT systems even less secure due to the inherent constraints associated with many IoT devices. These constraints, which are mainly imposed by cost since many IoT edge devices are expected to be inexpensive and disposable, include limited energy resources, limited computational and storage capabilities, as well as lossy networks due to the much lower hardware performance compared to conventional computers. While there are many security and privacy issues in the IoT today, arguably a root cause of such issues is that many start-up IoT device manufacturers and smart apps development companies do not adhere to the concept of security by design. Consequently, some of these companies produce IoT devices and smart apps with security vulnerabilities. In recent years, attackers have exploited different security vulnerabilities in IoT infrastructures which have caused several data breaches and other security and privacy incidents involving IoT devices and smart apps. These have attracted significant attention from the research community in both academia and industry, resulting in a surge of proposals put forward by many researchers. Although research approaches and findings may vary across different research studies, the consensus is that a fundamental prerequisite for addressing IoT security and privacy challenges is to build security and privacy protection into IoT devices and smart apps from the very beginning. To this end, this thesis investigates how to bake security and privacy into IoT systems from the onset, and as its main objective, this thesis particularly focuses on providing a solution that can foster the design and development of secure IoT devices and smart apps, namely the IoT Hardware Platform Security Advisor (IoT-HarPSecA) framework. The security framework is expected to provide support to designers and developers in IoT start-up companies during the design and implementation of IoT systems. IoT-HarPSecA framework is also expected to facilitate the implementation of security in existing IoT systems. To accomplish the previously mentioned objective as well as to affirm the aforementioned assertion, the following step-by-step problem-solving approach is followed. The first step is an exhaustive survey of different aspects of IoT security and privacy, including security requirements in IoT architecture, security threats in IoT architecture, IoT application domains and their associated cyber assets, the complexity of IoT vulnerabilities, and some possible IoT security and privacy countermeasures; and the survey wraps up with a brief overview of IoT hardware development platforms. The next steps are the identification of many challenges and issues associated with the IoT, which narrowed down to the abovementioned fundamental security/privacy issue; followed by a study of different aspects of security implementation in the IoT. The remaining steps are the framework design thinking process, framework design and implementation, and finally, framework performance evaluation. IoT-HarPSecA offers three functionality features, namely security requirement elicitation security best practice guidelines for secure development, and above all, a feature that recommends specific Lightweight Cryptographic Algorithms (LWCAs) for both software and hardware implementations. Accordingly, IoT-HarPSecA is composed of three main components, namely Security Requirements Elicitation (SRE) component, Security Best Practice Guidelines (SBPG) component, and Lightweight Cryptographic Algorithms Recommendation (LWCAR) component, each of them servicing one of the aforementioned features. The author has implemented a command-line tool in C++ to serve as an interface between users and the security framework. This thesis presents a detailed description, design, and implementation of the SRE, SBPG, and LWCAR components of the security framework. It also presents real-world practical scenarios that show how IoT-HarPSecA can be used to elicit security requirements, generate security best practices, and recommend appropriate LWCAs based on user inputs. Furthermore, the thesis presents performance evaluation of the SRE, SBPG, and LWCAR components framework tools, which shows that IoT-HarPSecA can serve as a roadmap for secure IoT development.O termo Internet das coisas (IoT) é utilizado para descrever um ecossistema, em expansão, de objetos físicos ou elementos interconetados entre si e à Internet. Os dispositivos IoT consistem numa gama vasta e heterogénea de objetos animados ou inanimados e, neste contexto, podem pertencer à IoT um indivíduo com um implante que monitoriza a frequência cardíaca ou até mesmo um animal de estimação que tenha um biochip. Estes dispositivos variam entre eletrodomésticos, tais como máquinas de café ou lâmpadas inteligentes, a ferramentas sofisticadas de uso na automatização industrial. A IoT está a revolucionar e a provocar mudanças em várias indústrias e muitas adotam esta tecnologia para incrementar as suas vantagens competitivas. Este paradigma melhora a eficiência operacional e otimiza o desempenho de sistemas através da gestão de dados em tempo real, resultando num balanço otimizado entre o uso energético e a taxa de transferência. Outra área de aplicação é a IoT Industrial (IIoT) ou internet industrial ou Indústria 4.0, ou seja, uma aplicação de IoT no âmbito industrial, onde os sistemas ciberfísicos estão interconectados a diversas tecnologias de forma a obter um controlo de rede sem fios, bem como fabricações avançadas e automatização fabril. As aplicações da IoT estão a crescer e a tornarem-se predominantes em muitos domínios de aplicação inteligentes como sistemas de saúde, cidades, redes, agricultura e sistemas de fornecimento. Da mesma forma, a IoT está a transformar estilos de vida e de trabalho e assim, a procura por produtos inteligentes está constantemente a aumentar. As grandes indústrias e startups competem entre si de forma a dominar o mercado com os seus novos serviços e produtos IoT, desbloqueando o valor de negócio da IoT. Apesar da sua crescente popularidade, benefícios e capacidades comprovadas, a IoT está ainda a dar os seus primeiros passos e é confrontada com muitos desafios. Entre eles, problemas de conectividade, compatibilidade/interoperabilidade entre dispositivos e sistemas, falta de padronização, gestão das enormes quantidades de dados e ainda falta de ferramentas para investigações forenses. No entanto, preocupações quanto ao estado de segurança e privacidade ainda estão entre os fatores adversos à adesão universal desta tecnologia. Estudos recentes revelaram que existem questões de segurança e privacidade associadas ao design e implementação de vários dispositivos IoT e aplicações inteligentes (smart apps.), isto pode ser devido ao facto, em parte, de que alguns fabricantes e empresas de desenvolvimento de dispositivos (especialmente startups) IoT e smart apps., recolham o valor de negócio dos grandes mercados IoT, negligenciando assim a importância da segurança, resultando em dispositivos IoT e smart apps. com carências e violações de segurança da IoT nos últimos anos. Esta tese aborda os desafios de segurança e privacidade que foram supra mencionados. Visto que a Internet e os sistemas informáticos tradicionais são por vezes considerados inseguros, os sistemas IoT tornam-se ainda mais inseguros, devido a restrições inerentes a tais dispositivos. Estas restrições são impostas devido ao custo, uma vez que se espera que muitos dispositivos de ponta sejam de baixo custo e descartáveis, com recursos energéticos limitados, bem como limitações na capacidade de armazenamento e computacionais, e redes com perdas devido a um desempenho de hardware de qualidade inferior, quando comparados com computadores convencionais. Uma das raízes do problema é o facto de que muitos fabricantes, startups e empresas de desenvolvimento destes dispositivos e smart apps não adiram ao conceito de segurança por construção, ou seja, logo na conceção, não preveem a proteção da privacidade e segurança. Assim, alguns dos produtos e dispositivos produzidos apresentam vulnerabilidades na segurança. Nos últimos anos, hackers maliciosos têm explorado diferentes vulnerabilidades de segurança nas infraestruturas da IoT, causando violações de dados e outros incidentes de privacidade envolvendo dispositivos IoT e smart apps. Estes têm atraído uma atenção significativa por parte das comunidades académica e industrial, que culminaram num grande número de propostas apresentadas por investigadores científicos. Ainda que as abordagens de pesquisa e os resultados variem entre os diferentes estudos, há um consenso e pré-requisito fundamental para enfrentar os desafios de privacidade e segurança da IoT, que buscam construir proteção de segurança e privacidade em dispositivos IoT e smart apps. desde o fabrico. Para esta finalidade, esta tese investiga como produzir segurança e privacidade destes sistemas desde a produção, e como principal objetivo, concentra-se em fornecer soluções que possam promover a conceção e o desenvolvimento de dispositivos IoT e smart apps., nomeadamente um conjunto de ferramentas chamado Consultor de Segurança da Plataforma de Hardware da IoT (IoT-HarPSecA). Espera-se que o conjunto de ferramentas forneça apoio a designers e programadores em startups durante a conceção e implementação destes sistemas ou que facilite a integração de mecanismos de segurança nos sistemas préexistentes. De modo a alcançar o objetivo proposto, recorre-se à seguinte abordagem. A primeira fase consiste num levantamento exaustivo de diferentes aspetos da segurança e privacidade na IoT, incluindo requisitos de segurança na arquitetura da IoT e ameaças à sua segurança, os seus domínios de aplicação e os ativos cibernéticos associados, a complexidade das vulnerabilidades da IoT e ainda possíveis contramedidas relacionadas com a segurança e privacidade. Evolui-se para uma breve visão geral das plataformas de desenvolvimento de hardware da IoT. As fases seguintes consistem na identificação dos desafios e questões associadas à IoT, que foram restringidos às questões de segurança e privacidade. As demais etapas abordam o processo de pensamento de conceção (design thinking), design e implementação e, finalmente, a avaliação do desempenho. O IoT-HarPSecA é composto por três componentes principais: a Obtenção de Requisitos de Segurança (SRE), Orientações de Melhores Práticas de Segurança (SBPG) e a recomendação de Componentes de Algoritmos Criptográficos Leves (LWCAR) na implementação de software e hardware. O autor implementou uma ferramenta em linha de comandos usando linguagem C++ que serve como interface entre os utilizadores e a IoT-HarPSecA. Esta tese apresenta ainda uma descrição detalhada, desenho e implementação das componentes SRE, SBPG, e LWCAR. Apresenta ainda cenários práticos do mundo real que demostram como o IoT-HarPSecA pode ser utilizado para elicitar requisitos de segurança, gerar boas práticas de segurança (em termos de recomendações de implementação) e recomendar algoritmos criptográficos leves apropriados com base no contributo dos utilizadores. De igual forma, apresenta-se a avaliação do desempenho destes três componentes, demonstrando que o IoT-HarPSecA pode servir como um roteiro para o desenvolvimento seguro da IoT

Cybersecurity applications of Blockchain technologies

With the increase in connectivity, the popularization of cloud services, and the rise of the Internet of Things (IoT), decentralized approaches for trust management are gaining momentum. Since blockchain technologies provide a distributed ledger, they are receiving massive attention from the research community in different application fields. However, this technology does not provide cybersecurity by itself. Thus, this thesis first aims to provide a comprehensive review of techniques and elements that have been proposed to achieve cybersecurity in blockchain-based systems. The analysis is intended to target area researchers, cybersecurity specialists and blockchain developers. We present a series of lessons learned as well. One of them is the rise of Ethereum as one of the most used technologies. Furthermore, some intrinsic characteristics of the blockchain, like permanent availability and immutability made it interesting for other ends, namely as covert channels and malicious purposes. On the one hand, the use of blockchains by malwares has not been characterized yet. Therefore, this thesis also analyzes the current state of the art in this area. One of the lessons learned is that covert communications have received little attention. On the other hand, although previous works have analyzed the feasibility of covert channels in a particular blockchain technology called Bitcoin, no previous work has explored the use of Ethereum to establish a covert channel considering all transaction fields and smart contracts. To foster further defence-oriented research, two novel mechanisms are presented on this thesis. First, Zephyrus takes advantage of all Ethereum fields and smartcontract bytecode. Second, Smart-Zephyrus is built to complement Zephyrus by leveraging smart contracts written in Solidity. We also assess the mechanisms feasibility and cost. Our experiments show that Zephyrus, in the best case, can embed 40 Kbits in 0.57 s. for US$1.64, and retrieve them in 2.8 s. Smart-Zephyrus, however, is able to hide a 4 Kb secret in 41 s. While being expensive (around US$ 1.82 per bit), the provided stealthiness might be worth the price for attackers. Furthermore, these two mechanisms can be combined to increase capacity and reduce costs.Debido al aumento de la conectividad, la popularización de los servicios en la nube y el auge del Internet de las cosas (IoT), los enfoques descentralizados para la gestión de la confianza están cobrando impulso. Dado que las tecnologías de cadena de bloques (blockchain) proporcionan un archivo distribuido, están recibiendo una atención masiva por parte de la comunidad investigadora en diferentes campos de aplicación. Sin embargo, esta tecnología no proporciona ciberseguridad por sí misma. Por lo tanto, esta tesis tiene como primer objetivo proporcionar una revisión exhaustiva de las técnicas y elementos que se han propuesto para lograr la ciberseguridad en los sistemas basados en blockchain. Este análisis está dirigido a investigadores del área, especialistas en ciberseguridad y desarrolladores de blockchain. A su vez, se presentan una serie de lecciones aprendidas, siendo una de ellas el auge de Ethereum como una de las tecnologías más utilizadas. Asimismo, algunas características intrínsecas de la blockchain, como la disponibilidad permanente y la inmutabilidad, la hacen interesante para otros fines, concretamente como canal encubierto y con fines maliciosos. Por una parte, aún no se ha caracterizado el uso de la blockchain por parte de malwares. Por ello, esta tesis también analiza el actual estado del arte en este ámbito. Una de las lecciones aprendidas al analizar los datos es que las comunicaciones encubiertas han recibido poca atención. Por otro lado, aunque trabajos anteriores han analizado la viabilidad de los canales encubiertos en una tecnología blockchain concreta llamada Bitcoin, ningún trabajo anterior ha explorado el uso de Ethereum para establecer un canal encubierto considerando todos los campos de transacción y contratos inteligentes. Con el objetivo de fomentar una mayor investigación orientada a la defensa, en esta tesis se presentan dos mecanismos novedosos. En primer lugar, Zephyrus aprovecha todos los campos de Ethereum y el bytecode de los contratos inteligentes. En segundo lugar, Smart-Zephyrus complementa Zephyrus aprovechando los contratos inteligentes escritos en Solidity. Se evalúa, también, la viabilidad y el coste de ambos mecanismos. Los resultados muestran que Zephyrus, en el mejor de los casos, puede ocultar 40 Kbits en 0,57 s. por 1,64 US$, y recuperarlos en 2,8 s. Smart-Zephyrus, por su parte, es capaz de ocultar un secreto de 4 Kb en 41 s. Si bien es cierto que es caro (alrededor de 1,82 dólares por bit), el sigilo proporcionado podría valer la pena para los atacantes. Además, estos dos mecanismos pueden combinarse para aumentar la capacidad y reducir los costesPrograma de Doctorado en Ciencia y Tecnología Informática por la Universidad Carlos III de MadridPresidente: José Manuel Estévez Tapiador.- Secretario: Jorge Blasco Alís.- Vocal: Luis Hernández Encina

Security and Privacy for Modern Wireless Communication Systems

The aim of this reprint focuses on the latest protocol research, software/hardware development and implementation, and system architecture design in addressing emerging security and privacy issues for modern wireless communication networks. Relevant topics include, but are not limited to, the following: deep-learning-based security and privacy design; covert communications; information-theoretical foundations for advanced security and privacy techniques; lightweight cryptography for power constrained networks; physical layer key generation; prototypes and testbeds for security and privacy solutions; encryption and decryption algorithm for low-latency constrained networks; security protocols for modern wireless communication networks; network intrusion detection; physical layer design with security consideration; anonymity in data transmission; vulnerabilities in security and privacy in modern wireless communication networks; challenges of security and privacy in node–edge–cloud computation; security and privacy design for low-power wide-area IoT networks; security and privacy design for vehicle networks; security and privacy design for underwater communications networks

Data Hiding and Its Applications

Data hiding techniques have been widely used to provide copyright protection, data integrity, covert communication, non-repudiation, and authentication, among other applications. In the context of the increased dissemination and distribution of multimedia content over the internet, data hiding methods, such as digital watermarking and steganography, are becoming increasingly relevant in providing multimedia security. The goal of this book is to focus on the improvement of data hiding algorithms and their different applications (both traditional and emerging), bringing together researchers and practitioners from different research fields, including data hiding, signal processing, cryptography, and information theory, among others

Assessing Canada's Copyright Law in the Digital Context: Digital Locks, Open Licenses, and the Limits of Legislative Change

This dissertation examines Canadas copyright law reform in the information age. The overarching theme of my research underscores the importance of considering the purpose(s) of copyright law and the public interest while navigating the copyright law reform process. Additionally, I advocate that in regulating the influence of technology in the copyright system, the default approach should aim to objectively balance the interests of stakeholders to the extent possible. Ultimately, recognizing that stakeholders will continue to develop pragmatic responses to the changing landscape through private contracting and technological measures, I suggest that embracing regulatory pluralism is the most promising path towards achieving balanced copyright in the digital age. I develop these arguments over six chapters