37 research outputs found
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Verifiable Random Functions
We efficiently combine unpredictability and verifiability by extending the Goldreich-Goldwasser-Micali notion of pseudorandom functions from a secret seed s, so that knowledge of not only enables one to evaluate at any point x, but also to provide an NP-proof that the value is indeed correct without compromising the unpredictability of at any other point for which no such a proof was provided.Engineering and Applied Science
Operator authentication and accountability for SCADA servers when requests are forwarded by a middle layer
Due to their critical nature, the actions performed by operators on Industrial Control Systems (ICS) are subject to source authentication and accountability. When commands are not send directly by the user, but forwarded by middle servers, the compromise of those severs threatens the security of the whole architecture. This Master thesis provides a solution for that problem, guaranteeing authentication end-to-end while fulfilling cost and performance requirements. Based on an analysis of several potential solutions, digital signatures were assessed to be the most flexible and secure option. Moreover, the proposed solution relies on Microsoft's Active Directory, which manages credentials on the target architecture, for securely linking public keys with user identities. A prototype implementation of the proposed design is included, together with a limited performance evaluation. They have proven the validity of the design, that guarantees end-to-end authentication and accountability of command requests, while maintaining low implementation and maintenance costs and a negligible impact in latency per message
Data Service Outsourcing and Privacy Protection in Mobile Internet
Mobile Internet data have the characteristics of large scale, variety of patterns, and complex association. On the one hand, it needs efficient data processing model to provide support for data services, and on the other hand, it needs certain computing resources to provide data security services. Due to the limited resources of mobile terminals, it is impossible to complete large-scale data computation and storage. However, outsourcing to third parties may cause some risks in user privacy protection. This monography focuses on key technologies of data service outsourcing and privacy protection, including the existing methods of data analysis and processing, the fine-grained data access control through effective user privacy protection mechanism, and the data sharing in the mobile Internet
Survey on Fully Homomorphic Encryption, Theory, and Applications
Data privacy concerns are increasing significantly in the context of Internet of Things, cloud services, edge computing, artificial intelligence applications, and other applications enabled by next generation networks. Homomorphic Encryption addresses privacy challenges by enabling multiple operations to be performed on encrypted messages without decryption. This paper comprehensively addresses homomorphic encryption from both theoretical and practical perspectives. The paper delves into the mathematical foundations required to understand fully homomorphic encryption (FHE). It consequently covers design fundamentals and security properties of FHE and describes the main FHE schemes based on various mathematical problems. On a more practical level, the paper presents a view on privacy-preserving Machine Learning using homomorphic encryption, then surveys FHE at length from an engineering angle, covering the potential application of FHE in fog computing, and cloud computing services. It also provides a comprehensive analysis of existing state-of-the-art FHE libraries and tools, implemented in software and hardware, and the performance thereof
Understanding Quantum Technologies 2022
Understanding Quantum Technologies 2022 is a creative-commons ebook that
provides a unique 360 degrees overview of quantum technologies from science and
technology to geopolitical and societal issues. It covers quantum physics
history, quantum physics 101, gate-based quantum computing, quantum computing
engineering (including quantum error corrections and quantum computing
energetics), quantum computing hardware (all qubit types, including quantum
annealing and quantum simulation paradigms, history, science, research,
implementation and vendors), quantum enabling technologies (cryogenics, control
electronics, photonics, components fabs, raw materials), quantum computing
algorithms, software development tools and use cases, unconventional computing
(potential alternatives to quantum and classical computing), quantum
telecommunications and cryptography, quantum sensing, quantum technologies
around the world, quantum technologies societal impact and even quantum fake
sciences. The main audience are computer science engineers, developers and IT
specialists as well as quantum scientists and students who want to acquire a
global view of how quantum technologies work, and particularly quantum
computing. This version is an extensive update to the 2021 edition published in
October 2021.Comment: 1132 pages, 920 figures, Letter forma
Volume 28, Number 11 (November 1910)
Some Approximate Pronunciations of the Names of French Musicians
How Verdi Preserved His Originality
Lessons with Franz Liszt
Weber\u27s Mistake
Cultivating Musical Taste in the Public Schools
Tschaikowski\u27s Ideals
Triumph of Edward MacDowell
Wagner on Mendelssohn and Schumann
Beware of Fraudulent Publishers
Survival of the Fittest in Music: How the Great Works of the Tonal Art Remain Through the Centuries, While Those of Less Value Are Doomed to More or Less Certain Oblivion
Just Ordinary Miss Brown: The Story of an Old-fashioned Teacher and How She Got Real Results While Others Failed
What to Do at the First Lesson: The Young Teacher\u27s Preparation
Sound-Reproducing Machine in Music Study
How Much Shall I Practice?
Well Known Composers of To-Day—H.W. Petriehttps://digitalcommons.gardner-webb.edu/etude/1563/thumbnail.jp
In case of emergency, do not break the glass!:Secure cross-organisational data sharing in acute care
Distributed Protocols with Threshold and General Trust Assumptions
Distributed systems today power almost all online applications. Consequently, a wide range of distributed protocols, such as consensus, and distributed cryptographic primitives are being researched and deployed in practice. This thesis addresses multiple aspects of distributed protocols and cryptographic schemes, enhancing their resilience, efficiency, and scalability.
Fundamental to every secure distributed protocols are its trust assumptions. These assumptions not only measure a protocol's resilience but also determine its scope of application, as well as, in some sense, the expressiveness and freedom of the participating parties. Dominant in practice is so far the threshold setting, where at most some f out of the n parties may fail in any execution. However, in this setting, all parties are viewed as identical, making correlations indescribable. These constraints can be surpassed with general trust assumptions, which allow arbitrary sets of parties to fail in an execution. Despite significant theoretical efforts, relevant practical aspects of this setting are yet to be addressed. Our work fills this gap. We show how general trust assumptions can be efficiently specified, encoded, and used in distributed protocols and cryptographic schemes. Additionally, we investigate a consensus protocol and distributed cryptographic schemes with general trust assumptions. Moreover, we show how the general trust assumptions of different systems, with intersecting or disjoint sets of participants, can be composed into a unified system.
When it comes to decentralized systems, such as blockchains, efficiency and scalability are often compromised due to the total ordering of all user transactions. Guerraoui (Distributed Computing, 2022) have contradicted the common design of major blockchains, proving that consensus is not required to prevent double-spending in a cryptocurrency. Modern blockchains support a variety of distributed applications beyond cryptocurrencies, which let users execute arbitrary code in a distributed and decentralized fashion. In this work we explore the synchronization requirements of a family of Ethereum smart contracts and formally establish the subsets of participants that need to synchronize their transactions.
Moreover, a common requirement of all asynchronous consensus protocols is randomness. A simple and efficient approach is to employ threshold cryptography for this. However, this necessitates in practice a distributed setup protocol, often leading to performance bottlenecks. Blum (TCC 2020) propose a solution bypassing this requirement, which is, however, practically inefficient, due to the employment of fully homomorphic encryption. Recognizing that randomness for consensus does not need to be perfect (that is, always unpredictable and agreed-upon) we propose a practical and concretely-efficient protocol for randomness generation.
Lastly, this thesis addresses the issue of deniability in distributed systems. The problem arises from the fact that a digital signature authenticates a message for an indefinite period. We introduce a scheme that allows the recipients to verify signatures, while allowing plausible deniability for signers. This scheme transforms a polynomial commitment scheme into a digital signature scheme
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Information Security and Privacy in Network Environments
This report focuses on policy issues in three areas: 1 ) national cryptography policy, including federal information processing standards and export controls; 2) guidance on safeguarding unclassified information in federal agencies; and 3) legal issues and information security, including electronic commerce, privacy, and intellectual property