Download or read book Heuristically Secure Threshold Lattice based Cryptography Schemes written by and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In public-key encryption, a long-term private key can be an easy target for hacking and deserves extra protection. One way to enhance its security is to share the long-term private key among multiple (say n) distributed servers; any threshold number (t, t ≤ n) of these servers are needed to collectively use the shared private key without reconstructing it. As a result, an attacker who has compromised less than t servers will still not be able to reconstruct the shared private key.In this thesis, we studied threshold decryption schemes for lattice-based public-key en- cryption, which is one of the most promising post-quantum public-key encryption schemes. We developed threshold decryption schemes for Stinson's, the standard NTRU, and NTRU with Ring Learning with Errors (R-LWE) cryptosystems. Prototype implementations were developed for validating the functionality of these threshold decryption schemes. Our de- signs achieve heuristic security, and its security is supported by mechanisms similar to that of R-LWE.

Download or read book Lattice Based Cryptosystems written by Jiang Zhang and published by Springer Nature. This book was released on 2020-10-14 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on lattice-based cryptosystems, widely considered to be one of the most promising post-quantum cryptosystems and provides fundamental insights into how to construct provably secure cryptosystems from hard lattice problems. The concept of provable security is used to inform the choice of lattice tool for designing cryptosystems, including public-key encryption, identity-based encryption, attribute-based encryption, key change and digital signatures. Given its depth of coverage, the book especially appeals to graduate students and young researchers who plan to enter this research area.

Download or read book Cryptography and Coding written by Matthew G. Parker and published by Springer Science & Business Media. This book was released on 2009-12-07 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: The12thintheseriesofIMAConferencesonCryptographyandCodingwasheld at the Royal Agricultural College, Cirencester, December 15–17, 2009. The p- gram comprised 3 invited talks and 26 contributed talks. The contributed talks werechosenbyathoroughreviewingprocessfrom53submissions.Oftheinvited and contributed talks,28 arerepresentedaspapersin this volume. These papers are grouped loosely under the headings: Coding Theory, Symmetric Crypt- raphy, Security Protocols, Asymmetric Cryptography, Boolean Functions, and Side Channels and Implementations. Numerous people helped to make this conference a success. To begin with I would like to thank all members of the Technical Program Committee who put a great deal of e?ort into the reviewing process so as to ensure a hi- quality program. Moreover, I wish to thank a number of people, external to the committee, who also contributed reviews on the submitted papers. Thanks, of course,mustalso goto allauthorswho submitted papers to the conference,both those rejected and accepted. The review process was also greatly facilitated by the use of the Web-submission-and-review software, written by Shai Halevi of IBM Research, and I would like to thank him for making this package available to the community. The invited talks were given by Frank Kschischang, Ronald Cramer, and Alexander Pott, and two of these invitedtalksappearaspapersinthisvolume. A particular thanks goes to these invited speakers, each of whom is well-known, notonlyforbeingaworld-leaderintheir?eld,butalsofortheirparticularability to communicate their expertise in an enjoyable and stimulating manner.

Download or read book Lattice Based Cryptography Security Foundations and Constructions written by Adeline Roux-Langlois and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lattice-based cryptography is a branch of cryptography exploiting the presumed hardness of some well-known problems on lattices. Its main advantages are its simplicity, efficiency, and apparent security against quantum computers. The principle of the security proofs in lattice-based cryptography is to show that attacking a given scheme is at least as hard as solving a particular problem, as the Learning with Errors problem (LWE) or the Small Integer Solution problem (SIS). Then, by showing that those two problems are at least as hard to solve than a hard problem on lattices, presumed polynomial time intractable, we conclude that the constructed scheme is secure.In this thesis, we improve the foundation of the security proofs and build new cryptographic schemes. We study the hardness of the SIS and LWE problems, and of some of their variants on integer rings of cyclotomic fields and on modules on those rings. We show that there is a classical hardness proof for the LWE problem (Regev's prior reduction was quantum), and that the module variants of SIS and LWE are also hard to solve. We also give two new lattice-based group signature schemes, with security based on SIS and LWE. One is the first lattice-based group signature with logarithmic signature size in the number of users. And the other construction allows another functionality, verifier-local revocation. Finally, we improve the size of some parameters in the work on cryptographic multilinear maps of Garg, Gentry and Halevi in 2013.

Download or read book Thresholdizing Lattice Based Encryption Schemes written by Andrew Xia and published by . This book was released on 2019 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, we examine a variety of constructions based on secret sharing techniques applied on lattice-based cryptographic primitives constructed from the learning with erros (LWE) assumption. Using secret sharing techniques from [BGG+17], we show how to construct paradigms of threshold multi-key fully homomorphic encryption and predicate encryption. Through multi-key fully homomorphic encryption [MW16] and threshold fully homomorphic encryption, we can construct a low-round multi party computation (MPC) scheme with guaranteed output delivery, assuming honest majority in the semi-honest and malicious settings. Applying the secret sharing scheme on predicate encryption constructions from LWE [GVW15], we can obtain a distributed predicate encryption scheme.

Download or read book Progress in Cryptology LATINCRYPT 2010 written by Michel Abdalla and published by Springer. This book was released on 2010-07-30 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the proceedings of the First International Conference on Cryptology and Information Security in Latin America, LATINCRYPT 2010, held in Puebla, Mexico, on August 8-11, 2010. The 19 papers presented together with four invited talks were carefully reviewed and selected from 62 submissions. The topics covered are encryption, elliptic curves, implementation of pairings, implementation of cryptographic algorithms, cryptographic protocols and foundations, cryptanalysis of symmetric primitives, post-quantum cryptography, and side-channel attacks.

Download or read book Quantum Safe Cryptographic Primitives Using Lattice Based Algorithms written by Simran Choudhary and published by . This book was released on 2023-11-30 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On the Concrete Security of Lattice Based Cryptography written by Michael Walter and published by . This book was released on 2017 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lattice-based cryptography is an extraordinarily popular subfield of cryptography. But since it is also a very young field, practical proposals for lattice-based cryptographic primitives have only recently started to emerge. Turning a cryptographic scheme into an implementation poses a range of questions, the arguably most important one being its concrete security: how do we ensure that any practically conceivable adversary is unable to break the scheme? In this thesis, we address two issues that arise in this context. Part I is concerned with basing cryptanalytic tools on a sound theoretical foundation. The common approach to analyzing a concrete cryptographic primitive is to analyze the performance of known algorithms to estimate the attack complexity of a hypothetical adversary. This requires a thorough theoretical understanding of the best performing algorithms. Unfortunately, for many subclasses of lattice algorithms there is a gap in our understanding, which leads to problems in the cryptanalytic process. In this part of the thesis we address these issues in two closely related subclasses of such algorithms. We develop new algorithms and analyze existing ones and show that in both cases it is possible to obtain algorithms that are simultaneously well understood in theory and competitive in practice. In Part II we focus on an integral part of most lattice-based schemes: sampling from a specific distribution over the integers. Implementing such a sampler securely and efficiently can be challenging for distributions commonly used in lattice-based schemes. We introduce new tools and security proofs that reduce the precision requirements for samplers, allowing more efficient implementations in a wide range of settings while maintaining high levels of security. Finally, we propose a new sampling algorithms with a unique set of properties desirable for implementations of cryptographic primitives.

Download or read book Threshold Schemes for Cryptographic Primitives written by National Institute National Institute of Standards and Technology and published by Createspace Independent Publishing Platform. This book was released on 2018-07-26 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: NISTIR 8214 Released 1 March 2019 As cryptography becomes ubiquitous, it becomes increasingly relevant to address the potentially disastrous breakdowns resulting from differences between ideal and real implementations of cryptographic algorithms. These differences give rise to a range of attacks that exploit vulnerabilities in order to compromise diverse aspects of real-world implementations. Threshold schemes have the potential to enable secure modes of operation even when certain subsets of components are compromised. However, they also present new challenges for the standardization and validation of security assertions about their implementations. Why buy a book you can download for free? We print this book so you don't have to. First you gotta find a good clean (legible) copy and make sure it's the latest version (not always easy). Some documents found on the web are missing some pages or the image quality is so poor, they are difficult to read. We look over each document carefully and replace poor quality images by going back to the original source document. We proof each document to make sure it's all there - including all changes. If you find a good copy, you could print it using a network printer you share with 100 other people (typically its either out of paper or toner). If it's just a 10-page document, no problem, but if it's 250-pages, you will need to punch 3 holes in all those pages and put it in a 3-ring binder. Takes at least an hour. It's much more cost-effective to just order the latest version from Amazon.com This book includes original commentary which is copyright material. Note that government documents are in the public domain. We print these large documents as a service so you don't have to. The books are compact, tightly-bound, full-size (8 1/2 by 11 inches), with large text and glossy covers. 4th Watch Publishing Co. is a SDVOSB. www.usgovpub.com If you like the service we provide, please leave positive review on Amazon.com. Here are some other titles we publish on Amazon.com: NIST SP 800-56A Pair-Wise Key-Establishment Schemes Using Discrete LogarithmCryptography NIST SP 800-22 A Statistical Test Suite for Random and Pseudorandom NumberGenerators for Cryptographic Applications NIST SP 800-67 Recommendation for the Triple Data Encryption Standard (TDEA) BlockCipher NIST SP 800-111 Guide to Storage Encryption Technologies for End User Devices NIST SP 800-130 A Framework for Designing Cryptographic Key Management Systems NIST SP 800-131 Recommendation for Transitioning the Use of Cryptographic Algorithmsand Key Lengths NIST SP 800-133 Recommendation for Cryptographic Key Generation NIST SP 800-152 A Profile for U.S. Federal Cryptographic Key Management Systems NIST SP 800-175 Guideline for Using Cryptographic Standards in the Federal Government NISTIR 7977 NIST Cryptographic Standards and Guidelines Development Process NISTIR 8105 Report on Post-Quantum Cryptography NISTIR 8114 Report on Lightweight Cryptography FIPS PUB 140-2 Security Requirements for Cryptographic Modules FIPS PUB 197 Advanced Encryption Standard (AES), The Keyed-Hash MessageAuthentication Code (HMAC), Standards for Security Categorization of Federal Information andInformation Systems

Download or read book Gadgets and Gaussians in Lattice Based Cryptography written by Nicholas James Genise and published by . This book was released on 2019 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation explores optimal algorithms employed in lattice-based cryptographic schemes. Chapter 2 focuses on optimizing discrete gaussian sampling on "gadget" and algebraic lattices. These gaussian sampling algorithms are used in lattice-cryptography's most efficient trapdoor mechanism for the SIS and LWE problems: "MP12" trapdoors. However, this trapdoor mechanism was previously not optimized and inefficient (or not proven to be statistically correct) for structured lattices (ring-SIS/LWE), lattice-cryptography's most efficient form, where the modulus is often a prime. The algorithms in this chapter achieve optimality in this regime and have (already) resulted in drastic efficiency improvement in independent implementations. Chapter 3 digs deeper into the gadget lattice's associated algorithms. Specifically, we explore efficiently sampling a simple subgaussian distribution on gadget lattices, and we optimize LWE decoding on gadget lattices. These subgaussian sampling algorithms correspond to a randomized bit-decomposition needed in lattice-based schemes with homomorphic properties like fully homomorphic encryption (FHE). Next, we introduce a general class of "Chinese Remainder Theorem" (CRT) gadgets. These gadgets allow advanced lattice-based schemes to avoid multi-precision arithmetic when the applications modulus is larger than 64 bits. The algorithms presented in the first two chapters improve the efficiency of many lattice-based cryptosystems: digital signature schemes, identity-based encryption schemes, as well as more advanced schemes like fully-homomorphic encryption and attribute-based encryption. In the final chapter, we take a closer look at the random matrices used in trapdoor lattices. First, we revisit the constants in the concentration bounds of subgaussian random matrices. Then, we provide experimental evidence for a simple heuristic regarding the singular values of matrices with entries drawn from commonly used distributions in cryptography. Though the proofs in this chapter are dense, cryptographers need a strong understanding of the singular values of these matrices since their maximum singular value determines the concrete security of the trapdoor scheme's underlying SIS problem.

Download or read book Fundamentals of Cryptology written by Henk C. A. van Tilborg and published by . This book was released on 2000 with total page 491 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Lattice based Cryptography written by Rikke Bendlin and published by . This book was released on 2013 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Threshold Schemes for Cryptographic Primitives written by Luís T. A. N. Branda̋̋o and published by . This book was released on 2019 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Computer Security Division at the National Institute of Standards and Technology is interested in promoting the security of implementations of cryptographic primitives. This security depends not only on the theoretical properties of the primitives but also on the ability to withstand attacks on their implementations. It is thus important to mitigate breakdowns that result from differences between ideal and real implementations of cryptographic algorithms. This document overviews the possibility of implementing cryptographic primitives using threshold schemes, where multiple components contribute to the operation in a way that attains the desired security goals even if f out of n of its components are compromised. There is also an identified potential in providing resistance against side-channel attacks, which exploit inadvertent leakage from real implementations. Security goals of interest include the secrecy of cryptographic keys, as well as enhanced integrity and availability, among others. This document considers challenges and opportunities related to standardization of threshold schemes for cryptographic primitives. It includes examples illustrating security tradeoffs under variations of system model and adversaries. It enumerates several high-level characterizing features of threshold schemes, including the types of threshold, the communication interfaces (with the environment and between components), the executing platform (e.g., single device vs. multiple devices) and the setup and maintenance requirements. The document poses a number of questions, motivating aspects to take into account when considering standardization. A particular challenge is the development of criteria that may help guide a selection of threshold cryptographic schemes. An open question is deciding at what level each standard should be defined (e.g., specific base techniques vs. conceptualized functionalities) and which flexibility of parametrization they should allow. Suitability to testing and validation of implementations are also major concerns to be addressed. Overall, the document intends to support discussion about standardization, including motivating an engagement from stakeholders. This is a step towards enabling threshold cryptography within the US federal government and beyond.

Download or read book Lattice based Cryptanalysis for Secure Cryptosystems written by Md. Mokammel Haque and published by . This book was released on 2014 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this thesis is to investigate and improve the performance of practical lattice reduction algorithms in terms of their output quality and runtime. A related goal is to apply these results to the crptanalysis of lattic-based crypto schemes.

Download or read book Towards Practical Lattice based Cryptography written by Vadim Lyubashevsky and published by . This book was released on 2008 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lattice-based cryptography began with the seminal work of Ajtai (Ajtai '96) who showed that it is possible to build families of cryptographic functions in which breaking a randomly chosen element of the family is as hard as solving worst-case instances of lattice problems. This work generated great interest and resulted in constructions of many other cryptographic protocols with security based on worst-case lattice problems. An additional advantage of lattice-based primitives is that, unlike their counterparts based on factoring and discrete log, they are conjectured to be secure in the advent of quantum computing. The main disadvantage of lattice-based constructions is that they generally involve operations on, and storage of, large n x n matrices. This resulted in the schemes being rather inefficient and unsuitable for practical use. To cope with this inherent inefficiency, Micciancio proposed to build lattice-based primitives based on the worst-case hardness of lattices that have some additional structure. In (Micciancio '02), he showed how to build one-way functions, computable in almost linear time, with security based on worst-case problems on such lattices. While interesting from a theoretical perspective, one-way functions are not very useful in practice. Our goal in this thesis is to present constructions of practical and efficient cryptographic protocols whose security is based on worst-case hardness of lattice problems. We first show how to build collision-resistant hash functions whose security is based on the hardness of lattice problems in all lattices with a special structure. The special structure that the lattices possess is that they are ideals of certain polynomial rings. The hash functions that we build have almost linear running time, and in practice turn out to be essentially as efficient as ad-hoc constructions that have no provable security. We also give constructions of provably-secure identification and signature schemes whose asymptotic running times are almost linear (up to poly-logarithmic factors), and so these schemes are much more efficient than comparable primitives with security based on factoring and discrete log. Thus our work implies that by considering ideal lattices, it is possible to have the best of both worlds: security based on worst-case problems and optimal efficiency.

Download or read book Advances in Cryptology CRYPTO 2024 written by Leonid Reyzin and published by Springer Nature. This book was released on with total page 511 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied Cryptography written by Bruce Schneier and published by John Wiley & Sons. This book was released on 2017-05-25 with total page 937 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the world's most renowned security technologist, Bruce Schneier, this 20th Anniversary Edition is the most definitive reference on cryptography ever published and is the seminal work on cryptography. Cryptographic techniques have applications far beyond the obvious uses of encoding and decoding information. For developers who need to know about capabilities, such as digital signatures, that depend on cryptographic techniques, there's no better overview than Applied Cryptography, the definitive book on the subject. Bruce Schneier covers general classes of cryptographic protocols and then specific techniques, detailing the inner workings of real-world cryptographic algorithms including the Data Encryption Standard and RSA public-key cryptosystems. The book includes source-code listings and extensive advice on the practical aspects of cryptography implementation, such as the importance of generating truly random numbers and of keeping keys secure. ". . .the best introduction to cryptography I've ever seen. . . .The book the National Security Agency wanted never to be published. . . ." -Wired Magazine ". . .monumental . . . fascinating . . . comprehensive . . . the definitive work on cryptography for computer programmers . . ." -Dr. Dobb's Journal ". . .easily ranks as one of the most authoritative in its field." -PC Magazine The book details how programmers and electronic communications professionals can use cryptography-the technique of enciphering and deciphering messages-to maintain the privacy of computer data. It describes dozens of cryptography algorithms, gives practical advice on how to implement them into cryptographic software, and shows how they can be used to solve security problems. The book shows programmers who design computer applications, networks, and storage systems how they can build security into their software and systems. With a new Introduction by the author, this premium edition will be a keepsake for all those committed to computer and cyber security.