434 research outputs found
LIPIcs, Volume 251, ITCS 2023, Complete Volume
LIPIcs, Volume 251, ITCS 2023, Complete Volum
2023-2024 Catalog
The 2023-2024 Governors State University Undergraduate and Graduate Catalog is a comprehensive listing of current information regarding:Degree RequirementsCourse OfferingsUndergraduate and Graduate Rules and Regulation
Improvements on Device Independent and Semi-Device Independent Protocols of Randomness Expansion
To generate genuine random numbers, random number generators based on quantum theory are essential. However, ensuring that the process used to produce randomness meets desired security standards can pose challenges for traditional quantum random number generators. This thesis delves into Device Independent (DI) and Semi-Device Independent (semi-DI) protocols of randomness expansion, based on a minimal set of experimentally verifiable security assumptions. The security in DI protocols relies on the violation of Bell inequalities, which certify the quantum behavior of devices. The semi-DI protocols discussed in this thesis require the characterization of only one device - a power meter. These protocols exploit the fact that quantum states can be prepared such that they cannot be distinguished with certainty, thereby creating a randomness resource. In this study, we introduce enhanced DI and semi-DI protocols that surpass existing ones in terms of output randomness rate, security, or in some instances, both. Our analysis employs the Entropy Accumulation Theorem (EAT) to determine the extractable randomness for finite rounds. A notable contribution is the introduction of randomness expansion protocols that recycle input randomness, significantly enhancing finite round randomness rates for DI protocols based on the CHSH inequality violation. In the final section of the thesis, we delve into Generalized Probability Theories (GPTs), with a focus on Boxworld, the largest GPT capable of producing correlations consistent with relativity. A tractable criterion for identifying a Boxworld channel is presented
Robustness of implemented device-independent protocols against constrained leakage
Device-independent (DI) protocols have experienced significant progress in
recent years, with a series of demonstrations of DI randomness generation or
expansion, as well as DI quantum key distribution. However, existing security
proofs for those demonstrations rely on a typical assumption in DI
cryptography, that the devices do not leak any unwanted information to each
other or to an adversary. This assumption may be difficult to perfectly enforce
in practice. While there exist other DI security proofs that account for a
constrained amount of such leakage, the techniques used are somewhat unsuited
for analyzing the recent DI protocol demonstrations. In this work, we address
this issue by studying a constrained leakage model suited for this purpose,
which should also be relevant for future similar experiments. Our proof
structure is compatible with recent proof techniques for flexibly analyzing a
wide range of DI protocol implementations. With our approach, we compute some
estimates of the effects of leakage on the keyrates of those protocols, hence
providing a clearer understanding of the amount of leakage that can be allowed
while still obtaining positive keyrates.Comment: Changelog: more detailed analysis of conditioning on acceptance
events, implemented tighter version of fidelity constraints and replaced SDP
formulation with more stable approach, updated figures accordingl
Private set intersection: A systematic literature review
Secure Multi-party Computation (SMPC) is a family of protocols which allow some parties to compute a function on their private inputs, obtaining the output at the end and nothing more. In this work, we focus on a particular SMPC problem named Private Set Intersection (PSI). The challenge in PSI is how two or more parties can compute the intersection of their private input sets, while the elements that are not in the intersection remain private. This problem has attracted the attention of many researchers because of its wide variety of applications, contributing to the proliferation of many different approaches. Despite that, current PSI protocols still require heavy cryptographic assumptions that may be unrealistic in some scenarios. In this paper, we perform a Systematic Literature Review of PSI solutions, with the objective of analyzing the main scenarios where PSI has been studied and giving the reader a general taxonomy of the problem together with a general understanding of the most common tools used to solve it. We also analyze the performance using different metrics, trying to determine if PSI is mature enough to be used in realistic scenarios, identifying the pros and cons of each protocol and the remaining open problems.This work has been partially supported by the projects: BIGPrivDATA (UMA20-FEDERJA-082) from the FEDER AndalucÃa 2014–
2020 Program and SecTwin 5.0 funded by the Ministry of Science and Innovation, Spain, and the European Union (Next Generation EU) (TED2021-129830B-I00). The first author has been funded by the Spanish Ministry of Education under the National F.P.U. Program (FPU19/01118). Funding for open access charge: Universidad de Málaga/CBU
Round-Optimal Black-Box Multiparty Computation from Polynomial-Time Assumptions
A central direction of research in secure multiparty computation with dishonest majority
has been to achieve three main goals:
1. reduce the total number of rounds of communication (to four, which is optimal);
2. use only polynomial-time hardness assumptions, and
3. rely solely on cryptographic assumptions in a black-box manner.
This is especially challenging when we do not allow a trusted setup assumption of any kind. While protocols achieving two out of three goals in this setting have been designed in recent literature, achieving all three simultaneously remained an elusive open question. Specifically, it was answered positively only for a restricted class of functionalities. In this paper, we completely resolve this long-standing open question. Specifically, we present a protocol for all polynomial-time computable functions that does not require any trusted setup assumptions and achieves all three of the above goals simultaneously
LIPIcs, Volume 261, ICALP 2023, Complete Volume
LIPIcs, Volume 261, ICALP 2023, Complete Volum
Efficient NIZKs for Algebraic Sets
Significantly extending the framework of (Couteau and Hartmann, Crypto 2020), we propose a general methodology to construct NIZKs for showing that an encrypted vector belongs to an algebraic set, i.e., is in the zero locus of an ideal of a polynomial ring. In the case where is principal, i.e., generated by a single polynomial , we first construct a matrix that is a ``quasideterminantal representation\u27\u27 of and then a NIZK argument to show that . This leads to compact NIZKs for general computational structures, such as polynomial-size algebraic branching programs. We extend the framework to the case where \IDEAL is non-principal, obtaining efficient NIZKs for R1CS, arithmetic constraint satisfaction systems, and thus for . As an independent result, we explicitly describe the corresponding language of ciphertexts as an algebraic language, with smaller parameters than in previous constructions that were based on the disjunction of algebraic languages. This results in an efficient GL-SPHF for algebraic branching programs
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