A Study on “Security of Cyber-Physical Systems in the Cloud”

The existing security models are built with certain assumptions. The solutions like distributed accountability, provable data possession (PDP), Third Party Auditing (TPA) and so on are secure as long as the assumptions hold true. To ensure fool proof security for cloud storage security little research has been made on quantum key cryptography. Since the quantum key distribution is unconditionally secure, we propose a new scheme known as Cloud QKDP (Quantum Key Distribution Protocol for Cloud Computing) which exploits the benefits of quantum mechanisms to secure cloud storage and data dynamics. We consider a case study in which three parties such as cloud server, data owner and trusted client have provably secure communications with our proposed scheme which uses random oracle model. Our empirical study revealed mixture of success and failure rates with private and public clouds respectively

Compress-store on blockchain: a decentralized data processing and immutable storage for multimedia streaming

Decentralization for data storage is a challenging problem for blockchain-based solutions as the blocksize plays a key role for scalability. In addition, specific requirements of multimedia data call for various changes in the blockchain technology internals. Considering one of the most popular applications of secure multimedia streaming, i.e., video surveillance, it is not clear how to judiciously encode incentivization, immutability, and compression into a viable ecosystem. In this study, we provide a genuine scheme that achieves this encoding for a video surveillance application. The proposed scheme provides a novel integration of data compression, immutable off-chain data storage using a new consensus protocol namely, Proof-of-WorkStore (PoWS) in order to enable fully useful work to be performed by the miner nodes of the network. The proposed idea is the first step towards achieving greener application of a blockchain-based environment to the video storage business that utilizes system resources efficiently.WOS:000773171200001Scopus - Affiliation ID: 60105072Science Citation Index ExpandedQ2 - Q4Article; Early AccessUluslararası işbirliği ile yapılan - EVETNisan2022YÖK - 2021-22Mar

Bilinear Pairing Based Encryption for Sensor Network

In this letter, we review some research efforts in the area of Pairing based encryption for data transmission and storage taking note of the computational overhead and consequently present a simple encryption scheme to buttress our initiative further

A Survey on Exotic Signatures for Post-quantum Blockchain: Challenges and Research Directions

Blockchain technology provides efficient and secure solutions to various online activities by utilizing a wide range of cryptographic tools. In this article, we survey the existing literature on post-quantum secure digital signatures that possess exotic advanced features and that are crucial cryptographic tools used in the blockchain ecosystem for (1) account management, (2) consensus efficiency, (3) empowering scriptless blockchain, and (4) privacy. The exotic signatures that we particularly focus on in this work are the following: multi-/aggregate, threshold, adaptor, blind, and ring signatures. Herein the term "exotic"refers to signatures with properties that are not just beyond the norm for signatures, e.g., unforgeability, but also imbue new forms of functionalities. Our treatment of such exotic signatures includes discussions on existing challenges and future research directions in the post-quantum space. We hope that this article will help to foster further research to make post-quantum cryptography more accessible so that blockchain systems can be made ready in advance of the approaching quantum threats

Envisioning the Future of Cyber Security in Post-Quantum Era: A Survey on PQ Standardization, Applications, Challenges and Opportunities

The rise of quantum computers exposes vulnerabilities in current public key cryptographic protocols, necessitating the development of secure post-quantum (PQ) schemes. Hence, we conduct a comprehensive study on various PQ approaches, covering the constructional design, structural vulnerabilities, and offer security assessments, implementation evaluations, and a particular focus on side-channel attacks. We analyze global standardization processes, evaluate their metrics in relation to real-world applications, and primarily focus on standardized PQ schemes, selected additional signature competition candidates, and PQ-secure cutting-edge schemes beyond standardization. Finally, we present visions and potential future directions for a seamless transition to the PQ era

Security of Ubiquitous Computing Systems

The chapters in this open access book arise out of the EU Cost Action project Cryptacus, the objective of which was to improve and adapt existent cryptanalysis methodologies and tools to the ubiquitous computing framework. The cryptanalysis implemented lies along four axes: cryptographic models, cryptanalysis of building blocks, hardware and software security engineering, and security assessment of real-world systems. The authors are top-class researchers in security and cryptography, and the contributions are of value to researchers and practitioners in these domains. This book is open access under a CC BY license

Efficient signature verification and key revocation using identity based cryptography

Cryptography deals with the development and evaluation of procedures for securing digital information. It is essential whenever multiple entities want to communicate safely. One task of cryptography concerns digital signatures and the verification of a signer’s legitimacy requires trustworthy authentication and authorization. This is achieved by deploying cryptographic keys. When dynamic membership behavior and identity theft come into play, revocation of keys has to be addressed. Additionally, in use cases with limited networking, computational, or storage resources, efficiency is a key requirement for any solution. In this work we present a solution for signature verification and key revocation in constraned environments, e.g., in the Internet of Things (IoT). Where other mechanisms generate expensive overheads, we achieve revocation through a single multicast message without significant computational or storage overhead. Exploiting Identity Based Cryptography (IBC) complements the approach with efficient creation and verification of signatures. Our solution offers a framework for transforming a suitable signature scheme to a so-called Key Updatable Signature Scheme (KUSS) in three steps. Each step defines mathematical conditions for transformation and precise security notions. Thereby, the framework allows a novel combination of efficient Identity Based Signature (IBS) schemes with revocation mechanisms originally designed for confidentiality in group communications. Practical applicability of our framework is demonstrated by transforming four well-established IBS schemes based on Elliptic Curve Cryptography (ECC). The security of the resulting group Identity Based Signature (gIBS) schemes is carefully analyzed with techniques of Provable Security. We design and implement a testbed for evaluating these kind of cryptographic schemes on different computing- and networking hardware, typical for constrained environments. Measurements on this testbed provide evidence that the transformations are practicable and efficient. The revocation complexity in turn is significantly reduced compared to existing solutions. Some of our new schemes even outperform the signing process of the widely used Elliptic Curve Digital Signature Algorithm (ECDSA). The presented transformations allow future application on schemes beyond IBS or ECC. This includes use cases dealing with Post-Quantum Cryptography, where the revocation efficiency is similarly relevant. Our work provides the basis for such solutions currently under investigation.Die Kryptographie ist ein Instrument der Informationssicherheit und beschäftigt sich mit der Entwicklung und Evaluierung von Algorithmen zur Sicherung digitaler Werte. Sie ist für die sichere Kommunikation zwischen mehreren Entitäten unerlässlich. Ein Bestandteil sind digitale Signaturen, für deren Erstellung man kryptographische Schlüssel benötigt. Bei der Verifikation muss zusätzlich die Authentizität und die Autorisierung des Unterzeichners gewährleistet werden. Dafür müssen Schlüssel vertrauensvoll verteilt und verwaltet werden. Wenn sie in Kommunikationssystemen mit häufig wechselnden Teilnehmern zum Einsatz kommen, müssen die Schlüssel auch widerruflich sein. In Anwendungsfällen mit eingeschränkter Netz-, Rechen- und Speicherkapazität ist die Effizienz ein wichtiges Kriterium. Diese Arbeit liefert ein Rahmenwerk, mit dem Schlüssel effizient widerrufen und Signaturen effizient verifiziert werden können. Dabei fokussieren wir uns auf Szenarien aus dem Bereich des Internets der Dinge (IoT, Internet of Things). Im Gegensatz zu anderen Lösungen ermöglicht unser Ansatz den Widerruf von Schlüsseln mit einer einzelnen Nachricht innerhalb einer Kommunikationsgruppe. Dabei fällt nur geringer zusätzlicher Rechen- oder Speicheraufwand an. Ferner vervollständigt die Verwendung von Identitätsbasierter Kryptographie (IBC, Identity Based Cryptography) unsere Lösung mit effizienter Erstellung und Verifikation der Signaturen. Hierfür liefert die Arbeit eine dreistufige mathematische Transformation von geeigneten Signaturverfahren zu sogenannten Key Updatable Signature Schemes (KUSS). Neben einer präzisen Definition der Sicherheitsziele werden für jeden Schritt mathematische Vorbedingungen zur Transformation festgelegt. Dies ermöglicht die innovative Kombination von Identitätsbasierten Signaturen (IBS, Identity Based Signature) mit effizienten und sicheren Mechanismen zum Schlüsselaustausch, die ursprünglich für vertrauliche Gruppenkommunikation entwickelt wurden. Wir zeigen die erfolgreiche Anwendung der Transformationen auf vier etablierten IBSVerfahren. Die ausschließliche Verwendung von Verfahren auf Basis der Elliptic Curve Cryptography (ECC) erlaubt es, den geringen Kapazitäten der Zielgeräte gerecht zu werden. Eine Analyse aller vier sogenannten group Identity Based Signature (gIBS) Verfahren mit Techniken aus dem Forschungsgebiet der Beweisbaren Sicherheit zeigt, dass die zuvor definierten Sicherheitsziele erreicht werden. Zur praktischen Evaluierung unserer und ähnlicher kryptographischer Verfahren wird in dieser Arbeit eine Testumgebung entwickelt und mit IoT-typischen Rechen- und Netzmodulen bestückt. Hierdurch zeigt sich sowohl die praktische Anwendbarkeit der Transformationen als auch eine deutliche Reduktion der Komplexität gegenüber anderen Lösungsansätzen. Einige der von uns vorgeschlagenen Verfahren unterbieten gar die Laufzeiten des meistgenutzten Elliptic Curve Digital Signature Algorithm (ECDSA) bei der Erstellung der Signaturen. Die Systematik der Lösung erlaubt prinzipiell auch die Transformation von Verfahren jenseits von IBS und ECC. Dadurch können auch Anwendungsfälle aus dem Bereich der Post-Quanten-Kryptographie von unseren Ergebnissen profitieren. Die vorliegende Arbeit liefert die nötigen Grundlagen für solche Erweiterungen, die aktuell diskutiert und entwickelt werden