scholarly journals Round-Optimal Composable Blind Signatures in the Common Reference String Model

2006 ◽  
pp. 60-77 ◽  
Author(s):  
Marc Fischlin
Keyword(s):  
String Model ◽  
Common Reference ◽  
Blind Signatures ◽  
The Common ◽  
Common Reference String

scholarly journals A note on universal composable zero-knowledge in the common reference string model

2009 ◽  
Vol 410 (11) ◽  
pp. 1099-1108 ◽  
Author(s):  
Andrew C.C. Yao ◽  
Frances F. Yao ◽  
Yunlei Zhao
Keyword(s):  
String Model ◽  
Zero Knowledge ◽  
Common Reference ◽  
The Common ◽  
Common Reference String

scholarly journals Zero-Knowledge Proofs and String Commitments Withstanding Quantum Attacks

2004 ◽  
Vol 11 (9) ◽  
Author(s):  
Ivan B. Damgård ◽  
Serge Fehr ◽  
Louis Salvail
Keyword(s):  
String Model ◽  
Zero Knowledge ◽  
New Techniques ◽  
Common Reference ◽  
Commitment Schemes ◽  
Quantum Protocols ◽  
Hard Problems ◽  
The Common ◽  
Common Reference String ◽  
General Method

The concept of zero-knowledge (ZK) has become of fundamental importance in cryptography. However, in a setting where entities are modeled by quantum computers, classical arguments for proving ZK fail to hold since, in the quantum setting, the concept of rewinding is not generally applicable. Moreover, known classical techniques that avoid rewinding have various shortcomings in the quantum setting.<br /> <br />We propose new techniques for building <em>quantum</em> zero-knowledge (QZK) protocols, which remain secure even under (active) quantum attacks. We obtain computational QZK proofs and perfect QZK arguments for any NP language in the common reference string model. This is based on a general method converting an important class of classical honest-verifier ZK (HVZK) proofs into QZK proofs. This leads to quite practical protocols if the underlying HVZK proof is efficient. These are the first proof protocols enjoying these properties, in particular the first to achieve perfect QZK.<br /> <br />As part of our construction, we propose a general framework for building unconditionally hiding (trapdoor) string commitment schemes, secure against quantum attacks, as well as concrete instantiations based on specific (believed to be) hard problems. This is of independent interest, as these are the first unconditionally hiding string commitment schemes withstanding quantum attacks.<br /> <br />Finally, we give a partial answer to the question whether QZK is possible in the plain model. We propose a new notion of QZK, <em>non-oblivious verifier</em> QZK, which is strictly stronger than honest-verifier QZK but weaker than full QZK, and we show that this notion can be achieved by means of efficient (quantum) protocols.

scholarly journals Building Group Key Establishment on Group Theory: A Modular Approach

Symmetry ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 197
Author(s):  
Jens-Matthias Bohli ◽  
María I. González Vasco ◽  
Rainer Steinwandt
Keyword(s):  
Protocol Design ◽  
Key Establishment ◽  
Group Key ◽  
Common Reference ◽  
Ring Configuration ◽  
Diffie Hellman ◽  
Left And Right ◽  
The Common ◽  
Group Key Establishment ◽  
Common Reference String

A group key establishment protocol is presented and proven secure in the common reference string mode. The protocol builds on a group-theoretic assumption, and a concrete example can be obtained with a decision Diffie–Hellman assumption. The protocol is derived from a two-party solution by means of a protocol compiler presented by Abdalla et al. at TCC 2007, evidencing the possibility of meaningfully integrating cryptographic and group-theoretic tools in cryptographic protocol design. This compiler uses a standard ring configuration, where all users behave symmetrically, exchanging keys with their left and right neighbor, which are later combined to yield a shared group key.

scholarly journals Continuously Non-malleable Codes in the Split-State Model

2020 ◽  
Vol 33 (4) ◽  
pp. 2034-2077
Author(s):  
Sebastian Faust ◽  
Pratyay Mukherjee ◽  
Jesper Buus Nielsen ◽  
Daniele Venturi
Keyword(s):  
State Model ◽  
List Type ◽  
Cryptographic Primitives ◽  
Common Reference ◽  
Split State ◽  
The Common ◽  
Definition Of ◽  
State Code ◽  
Common Reference String ◽  
Trapdoor Permutations

Abstract Non-malleable codes (Dziembowski et al., ICS’10 and J. ACM’18) are a natural relaxation of error correcting/detecting codes with useful applications in cryptography. Informally, a code is non-malleable if an adversary trying to tamper with an encoding of a message can only leave it unchanged or modify it to the encoding of an unrelated value. This paper introduces continuous non-malleability, a generalization of standard non-malleability where the adversary is allowed to tamper continuously with the same encoding. This is in contrast to the standard definition of non-malleable codes, where the adversary can only tamper a single time. The only restriction is that after the first invalid codeword is ever generated, a special self-destruct mechanism is triggered and no further tampering is allowed; this restriction can easily be shown to be necessary. We focus on the split-state model, where an encoding consists of two parts and the tampering functions can be arbitrary as long as they act independently on each part. Our main contributions are outlined below. We show that continuous non-malleability in the split-state model is impossible without relying on computational assumptions. We construct a computationally secure split-state code satisfying continuous non-malleability in the common reference string (CRS) model. Our scheme can be instantiated assuming the existence of collision-resistant hash functions and (doubly enhanced) trapdoor permutations, but we also give concrete instantiations based on standard number-theoretic assumptions. We revisit the application of non-malleable codes to protecting arbitrary cryptographic primitives against related-key attacks. Previous applications of non-malleable codes in this setting required perfect erasures and the adversary to be restricted in memory. We show that continuously non-malleable codes allow to avoid these restrictions.

scholarly journals Randomized Oblivious Transfer for Secure Multiparty Computation in the Quantum Setting

Entropy ◽  
2021 ◽  
Vol 23 (8) ◽  
pp. 1001
Author(s):  
Bruno Costa ◽  
Pedro Branco ◽  
Manuel Goulão ◽  
Mariano Lemus ◽  
Paulo Mateus
Keyword(s):  
Building Block ◽  
Large Scale ◽  
String Model ◽  
Oblivious Transfer ◽  
Secure Computation ◽  
Multiparty Computation ◽  
Basic Building Block ◽  
Universal Composability ◽  
Common Reference ◽  
Common Reference String

Secure computation is a powerful cryptographic tool that encompasses the evaluation of any multivariate function with arbitrary inputs from mutually distrusting parties. The oblivious transfer primitive serves is a basic building block for the general task of secure multi-party computation. Therefore, analyzing the security in the universal composability framework becomes mandatory when dealing with multi-party computation protocols composed of oblivious transfer subroutines. Furthermore, since the required number of oblivious transfer instances scales with the size of the circuits, oblivious transfer remains as a bottleneck for large-scale multi-party computation implementations. Techniques that allow one to extend a small number of oblivious transfers into a larger one in an efficient way make use of the oblivious transfer variant called randomized oblivious transfer. In this work, we present randomized versions of two known oblivious transfer protocols, one quantum and another post-quantum with ring learning with an error assumption. We then prove their security in the quantum universal composability framework, in a common reference string model.

Secure Multiparty Computation

2018 ◽  
pp. 154-166
Author(s):  
Kannan Balasubramanian ◽  
M. Rajakani
Keyword(s):  
Data Mining ◽  
Public Key Infrastructure ◽  
Secure Multiparty Computation ◽  
Public Key ◽  
Multiparty Computation ◽  
Scientific Computation ◽  
Database Querying ◽  
Common Reference ◽  
Different Types ◽  
Common Reference String

The Secure Multiparty computation is characterized by computation by a set of multiple parties each participating using the private input they have. There are different types of models for Secure Multiparty computation based on assumption about the type of adversaries each model is assumed to protect against including Malicious and Covert Adversaries. The model may also assume a trusted setup with either using a Public Key Infrastructure or a using a Common Reference String. Secure Multiparty Computation has a number of applications including Scientific Computation, Database Querying and Data Mining.

scholarly journals The Spider Anatomy Ontology (SPD)—A Versatile Tool to Link Anatomy with Cross-Disciplinary Data

Diversity ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 202 ◽  
Author(s):  
Martín J. Ramírez ◽  
Peter Michalik
Keyword(s):  
Structural Complexity ◽  
Morphological Diversity ◽  
Biomedical Ontologies ◽  
Anatomy Ontology ◽  
Common Reference ◽  
Versatile Tool ◽  
Open Biomedical Ontologies ◽  
Reference Ontology ◽  
The Common ◽  
And Behavior

Spiders are a diverse group with a high eco-morphological diversity, which complicates anatomical descriptions especially with regard to its terminology. New terms are constantly proposed, and definitions and limits of anatomical concepts are regularly updated. Therefore, it is often challenging to find the correct terms, even for trained scientists, especially when the terminology has obstacles such as synonyms, disputed definitions, ambiguities, or homonyms. Here, we present the Spider Anatomy Ontology (SPD), which we developed combining the functionality of a glossary (a controlled defined vocabulary) with a network of formalized relations between terms that can be used to compute inferences. The SPD follows the guidelines of the Open Biomedical Ontologies and is available through the NCBO BioPortal (ver. 1.1). It constitutes of 757 valid terms and definitions, is rooted with the Common Anatomy Reference Ontology (CARO), and has cross references to other ontologies, especially of arthropods. The SPD offers a wealth of anatomical knowledge that can be used as a resource for any scientific study as, for example, to link images to phylogenetic datasets, compute structural complexity over phylogenies, and produce ancestral ontologies. By using a common reference in a standardized way, the SPD will help bridge diverse disciplines, such as genomics, taxonomy, systematics, evolution, ecology, and behavior.

Sign in / Sign up

Export Citation Format

Share Document