Reference String Research Articles

New Techniques for Noninteractive Zero-Knowledge

Noninteractive zero-knowledge (NIZK) proof systems are fundamental primitives used in many cryptographic constructions, including public-key encryption secure against chosen ciphertext attack, digital signatures, and various other cryptographic protocols. We introduce new techniques for constructing NIZK proofs based on groups with a bilinear map. Compared to previous constructions of NIZK proofs, our techniques yield dramatic reduction in the length of the common reference string (proportional to security parameter) and the size of the proofs (proportional to security parameter times the circuit size). Our novel techniques allow us to answer several long-standing open questions in the theory of noninteractive proofs. We construct the first perfect NIZK argument system for all NP. We construct the first universally composable NIZK argument for all NP in the presence of an adaptive adversary. We construct a non-interactive zap for all NP, which is the first that is based on a standard cryptographic security assumption.

An Efficient Non-interactive Universally Composable String-Commitment Scheme

This paper presents a new non-interactive string-commitment scheme that achieves universally composable security. Security is proven under the decisional composite residuosity (DCR) assumption (or the decisional Diffie-Hellman (DDH) assumption) in the common reference string (CRS) model. The universal composability (UC) is a very strong security notion. If cryptographic protocols are proven secure in the UC framework, then they remain secure even if they are composed with arbitrary protocols and polynomially many copies of the protocols are run concurrently. Many UC commitment schemes in the CRS model have been proposed, but they are either interactive commitment or bit-commitment (not string-commitment) schemes. We note, however, that although our scheme is the first non-interactive UC string-commitment scheme, a CRS is not reusable. We use an extension of all-but-one trapdoor functions (ABO-TDFs) proposed by Peikert and Waters at STOC 2008 as an essential building block. Our main idea is to extend (original deterministic) ABO-TDFs to probabilistic ones by using the homomorphic properties of their function indices. The function indices of ABO-TDFs consist of ciphertexts of homomorphic encryption schemes (such as ElGamal, and Damgard-Jurik encryption). Therefore we can re-randomize the output of ABO-TDFs by re-randomization of ciphertexts. This is a new application of ABO-TDFs.

A Multi-Trapdoor Commitment Scheme from the RSA Assumption

Gennaro introduced the notion of multi-trapdoor commitments which is a stronger form of trapdoor commitment schemes at CRYPTO 2004. Multi-trapdoor commitments have several cryptographic applications. For example, Gennaro proposed a conversion that makes a non-interactive multi-trapdoor commitment scheme into a noninteractive and reusable non-malleable commitment scheme and a compiler that transforms any proof of knowledge into concurrently nonmalleable one. Gennaro gave constructions of multi-trapdoor commitments, but they rely on stronger assumptions, such as the strong RSA assumption, the q-strong Diffie-Hellman assumption. In this paper, we propose a non-interactive multi-trapdoor commitment scheme from the standard RSA assumption. Thus, as a corollary of our result, we obtain a non-interactive and reusable non-malleable commitment scheme from the standard RSA assumption. Our scheme is based on theHohenberger-Waters signature scheme proposed at CRYPTO2009. Several non-interactive and reusable non-malleable commitment schemes (in the common reference string model) have been proposed, but all of them rely on stronger assumptions (e.g., strong RSA).

Sub-Linear Size Traceable Ring Signatures without Random Oracles

Traceable ring signatures, proposed at PKC'07, are a variant of ring signatures, which allow a signer to anonymously sign a message with a tag behind a ring, i.e., a group of users chosen by the signer, unless he signs two messages with the same tag. However, if a signer signs twice on the same tag, the two signatures will be linked and the identity of the signer will be revealed when the two signed messages are different. Traceable ring signatures can be applied to anonymous write-in voting without any special voting authority and electronic coupon services. The previous traceable ring signature scheme relies on random oracles at its security and the signature size is linear in the number of ring members. This paper proposes the first secure traceable ring signature schemes without random oracles in the common reference string model. In addition, the proposed schemes have a signature size of O(√N), where N is the number of users in the ring.

Undeniable and Unpretendable Signatures

Undeniable signature, and unpretendable signature schemes have been studied independently. In this paper, efficient schemes which serve as both at the same time are presented. The schemes find their typical application in anonymous auction where the winner cannot deny her bid; nobody can pretend to be the winner; and the anonymity of all losers is preserved. The security of the schemes is proved in the common reference string model under discrete logarithm type assumptions.

A framework for universally composable non-committing blind signatures

This paper studies non-committing type of universally composable (UC) blind signature protocols where an adversary does not necessarily commit to a message when requesting a signature. An ordinary UC blind signature functionality requires users to commit to the message to be blindly signed. It is thereby impossible to realise in the plain model. This paper first shows that even non-committing variants cannot be realised in the plain model. We then characterise UC non-committing blind signatures in the common reference string model by presenting equivalent stand-alone security notions under static corruption. The usefulness of the characterisation is demonstrated by showing that Fischlin's basic stand-alone blind signature scheme can be transformed into a UC non-committing blind signature protocol without using extra cryptographic components. We extend the results to the adaptive corruption model and present analogous notions, theorems, and constructions both in the erasure model and the non-erasure model.

Online license plate matching procedures using license-plate recognition machines and new weighted edit distance

License-plate recognition (LPR) technology has been widely applied in many different transportation applications such as enforcement, vehicle monitoring, and access control. Recently, there has been effort to exploit an LPR database for vehicle tracking using popular template matching procedures. Existing template matching procedures assume that the true reference string is always available. However, under a two-point LPR survey, a vehicle could have its plate misread at both locations generating a pair of misread strings (or templates) with no reference for matching. To compensate for LPR misreading problem, we propose a new weight function based on a probability model to match the observed outcomes of a dual LPR setup. Also, considering that reversal errors are never made in LPR machines, new editing constraints as a function of the string lengths are proposed to avoid compensation for reversal errors. These editing constraints are incorporated into the constraint edit distance formulation to improve the performance of the matching procedure. Finally, considering that previous template matching procedures do not take advantage of passage time information available in LPR databases, we present an online tracking procedure that considers the properties of probability distribution of vehicle journey times in order to increase the probability of correct matches. Experimental results show that our proposed procedure can improve the accuracy of LPR systems and achieve up to 97% of positive matches with no false matches. Further research is needed to extend the ideas proposed herein to plate-matching with multiple, i.e., more than two, LPR units.

Number representation using generalized [formula omitted]-transformation

We study non-standard number systems with negative base − β . Instead of the Ito–Sadahiro definition, based on the transformation T − β of the interval [ − β β + 1 , 1 β + 1 ) into itself, we suggest a generalization using an interval [ l , l + 1 ) with l ∈ ( − 1 , 0 ] . Such numeration systems share many properties of positive base numeration introduced by Rényi, although the proofs are not always straightforward. In this paper we focus on the description of admissible digit strings and their periodicity. We address the question of the description of reference strings used in the admissibility condition. We give examples which contradict a result of Góra and show that in this aspect the negative base numeration significantly differs from the Rényi numeration.

Secure Computation Without Authentication

Research on secure multiparty computation has mainly concentrated on the case where the parties can authenticate each other and the communication between them. This work addresses the question of what security can be guaranteed when authentication is not available. We consider a completely unauthenticated setting, where all messages sent by the parties may be tampered with and modified by the adversary without the uncorrupted parties being able to detect this fact. In this model, it is not possible to achieve the same level of security as in the authenticated-channel setting. Nevertheless, we show that meaningful security guarantees can be provided: Essentially, all the adversary can do is to partition the network into disjoint sets, where in each set the computation is secure in of itself, and also independent of the computation in the other sets. In this setting we provide, for the first time, nontrivial security guarantees in a model with no setup assumptions whatsoever. We also obtain similar results while guaranteeing universal composability, in some variants of the common reference string model. Finally, our protocols can be used to provide conceptually simple and unified solutions to a number of problems that were studied separately in the past, including password-based authenticated key exchange and nonmalleable commitments. As an application of our results, we study the question of constructing secure protocols in partially authenticated networks, where some of the links are authenticated, and some are not (as is the case in most networks today).

참조연계 서비스 구현을 위한 참고문헌 식별자 매칭 시스템

A reference linking service that is connection of each other different information resource need to setup the reference database and to match identifier. CrossRef, PubMed and Web Of Science etc. the many overseas agencies developed reference linking service, that they used the automatic tools of Inera eXstyles, Parity Computings Reference Extractor etc. and setup in base DOI and PMID etc. Domestic the various agencies of KISTI(Korea Institute Science and Technology of Information), KRF(Korea Research Foundation) etc are construction reference database. But each research communities adopts a various reference bibliography writing format. As, the data base construction which is collect is confronting is many to being difficult. In this paper, We developed the Citation Matcher System. This system is automatic parsing the reference string to metadata and matching DOI, PMID and KOI as Identifier. It is improved the effectiveness of reference database setup.

Impossibility Results for Universal Composability in Public-Key Models and with Fixed Inputs

Universal composability and concurrent general composition consider a setting where secure protocols are run concurrently with each other and with arbitrary other possibly insecure protocols. Protocols that meet the definition of universal composability are guaranteed to remain secure even when run in this strongly adversarial setting. In the case of an honest majority, or where there is a trusted setup phase of some kind (like a common reference string or the key-registration public-key infrastructure of Barak et al. in FOCS 2004), it has been shown that any functionality can be securely computed in a universally composable way. On the negative side, it has also been shown that in the plain model where there is no trusted setup at all, there are large classes of functionalities which cannot be securely computed in a universally composable way without an honest majority.In this paper, we extend these impossibility results for universal composability. We study a number of public-key models and show for which models the impossibility results of universal composability hold and for which they do not. We also consider a setting where the inputs to the protocols running in the network are fixed before any execution begins. The majority of our results are negative and we show that the known impossibility results for universal composability in the case of no honest majority extend to many other settings.

Long-Term Security and Universal Composability

Algorithmic progress and future technological advances threaten today’s cryptographic protocols. This may allow adversaries to break a protocol retrospectively by breaking the underlying complexity assumptions long after the execution of the protocol. Long-term secure protocols, protocols that after the end of the execution do not reveal any information to a then possibly unlimited adversary, could meet this threat. On the other hand, in many applications, it is necessary that a protocol is secure not only when executed alone, but within arbitrary contexts. The established notion of universal composability (UC) captures this requirement. This is the first paper to study protocols which are simultaneously long-term secure and universally composable. We show that the usual set-up assumptions used for UC protocols (e.g. a common reference string) are not sufficient to achieve long-term secure and composable protocols for commitments or zero-knowledge protocols. We give practical alternatives (e.g. signature cards) to these usual setup-assumptions and show that these enable the implementation of the important primitives commitment and zero-knowledge protocols.

Efficient and secure authenticated key exchange using weak passwords

Mutual authentication and authenticated key exchange are fundamental techniques for enabling secure communication over public, insecure networks. It is well known how to design secure protocols for achieving these goals when parties share high-entropy cryptographic keys in advance of the authentication stage. Unfortunately, it is much more common for users to share weak, low-entropy passwords which furthermore may be chosen from a known space of possibilities (say, a dictionary of English words). In this case, the problem becomes much more difficult as one must ensure that protocols are immune to off-line dictionary attacks in which an adversary exhaustively enumerates all possible passwords in an attempt to determine the correct one. We propose a 3-round protocol for password-only authenticated key exchange, and provide a rigorous proof of security for our protocol based on the decisional Diffie-Hellman assumption. The protocol assumes only public parameters—specifically, a “common reference string”—which can be “hard-coded” into an implementation of the protocol; in particular, and in contrast to some previous work, our protocol does not require either party to pre-share a public key. The protocol is also remarkably efficient, requiring computation only (roughly) 4 times greater than “classical” Diffie-Hellman key exchange that provides no authentication at all. Ours is the first protocol for password-only authentication that is both practical and provably-secure using standard cryptographic assumptions .

Universally Composable Mercurial Commitment Scheme

A mercurial commitment scheme is an interesting variation of a regular commitment scheme,which extends to allow for a soft decommit stage.The soft decommitments are not binding but can not conflict with the true decommmitments.The original application of mercurial commitment is to construct zero knowledge sets.The universally composable framework initiated by Canetti is very useful due to its ensuring stronger securities such as concurrent security,adaptive security,non-malleability,etc.This paper proposes a universally composable mercurial commitment scheme and proves its security in the common reference string(CRS) model.On one hand,the research on mercurial commitment scheme is deepened,on the other hand the result answers an open problem presented by Gennaro and Micali.

Blickbewegungsmuster erfahrener und unerfahrener Fahrer im Automobilsport

In analysing the information received by a driver of a motor vehicle, the visual system has an important position because the majority of sensation is processed through it. In this study, experienced drivers (ED) and inexperienced drivers (ID) were compared concerning scan path on a racetrack. Our intention was to study the problem that within each individual test group, similarities exist regarding the view of a complex and dynamic sequence. Furthermore, we analysed the concurrences in the scan path between the two compared test groups and whether we could verify a learning process for the ID. PROBANDS, MATERIALS, AND METHODS: The eye movement and scan path registrations of the eight probands (four ED and four ID) were measured with an eye tracking system based on the corneal reflex method. On the racetrack, the scan path of each proband was recorded with the eye tracking system and was analysed by special software. Therefore, the important objects were divided into areas of interest (AOI). The fixation duration results of the ID compared with the ED showed a 16.7% shorter fixation duration. The relative frequency of the scan path of the four most important AOI in bend 1 of the racetrack showed a significant difference (ED=78.85%; ID=30.25). The transition matrix showed a zero in all cell for 75% of the ED and 30.56% of the ID. The costs in the string editing for converting the comparing string in the reference string showed, on average, 12.5 costs for the ED and 50 costs for the ID. The learning process of the ID was demonstrated with the transition matrix (the increase in zeros from lap 1 to lap 3 was about 72.72%) and the relative frequency (an increase in observation of the four most important AOI from 20.76% to 34.76%). The results point to a learned scan path for the ED. Consequently, we were able to show an ideal scan path that emphasises a learning process for the ID.

Efficient Non-malleable Commitment Schemes

Non-malleability protects against man-in-the middle attacks on cryptographic protocols. Non-malleable commitment schemes, for example, assure that a commitment of a message does not help to produce a commitment of a related message. Here we present efficient constructions of such commitment schemes in the common reference string model, based on standard assumptions such as RSA, factoring or discrete logarithm. Our protocols require only three rounds and a few modular exponentiations, and provide statistical or even perfect secrecy of committed values. We also discuss differences between the notion of non-malleable commitment schemes used in previous works by Dolev, Dwork and Naor and by Di Crescenzo, Ishai and Ostrovsky. The former definition requires that it is infeasible to find a commitment such that there exists an encapsulated message which is related to another committed value (non-malleability with respect to commitment). The second approach allows the existence of such messages, but then it is hard to find them and to output them in the opening phase (non-malleability with respect to opening). We note that our solutions are of the second type.

How Anomalous Is Belady's Anomaly?

An international association advancing the multidisciplinary study of informing systems. Founded in 1998, the Informing Science Institute (ISI) is a global community of academics shaping the future of informing science.

Zero-Knowledge against Quantum Attacks

This paper proves that several interactive proof systems are zero-knowledge against general quantum attacks. This includes the well-known Goldreich-Micali-Wigderson classical zero-knowledge protocols for graph isomorphism and graph 3-coloring (assuming the existence of quantum computationally concealing commitment schemes in the second case). Also included is a quantum interactive proof system for a complete problem for the complexity class of problems having honest verifier quantum statistical zero-knowledge proofs, which therefore establishes that honest verifier and general quantum statistical zero-knowledge are equal: $\mathrm{QSZK}= \mathrm{QSZK}_{\mathrm{HV}}$. Previously no nontrivial interactive proof systems were known to be zero-knowledge against quantum attacks, except in restricted settings such as the honest verifier and common reference string models. This paper therefore establishes for the first time that true zero-knowledge is indeed possible in the presence of quantum information and computation.

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

Pass observed that universal composable zero-knowledge (UCZK) protocols in the common reference string (CRS) model lose deniability that is a natural security property and implication of the ZK functionality in accordance with the UC framework. An open problem (or, natural query) raised in the literature is: are there any other essential security properties, other than the well-known deniability property, that could be lost by UCZK in the CRS model, in comparison with the ZK functionality in accordance with the UC framework? In this work, we answer this open question (or, natural query), by showing that when running concurrently with other protocols UCZK in the CRS model can lose proof of knowledge (POK) property that is very essential and core security implication of the ZK functionality. This is demonstrated by concrete attack against naturally existing UCZK protocols in the CRS model. Then, motivated by our attack, we make further clarifications of the underlying reasons beneath the concrete attack, and investigate the precise security guarantee of UC with CRS.

A new approach for UC security concurrent deniable authentication

Deniable authentication protocols allow a sender to authenticate a message for a receiver, in a way which the receiver cannot convince a third party that such authentication ever took place. When we consider an asynchronous multi-party network with open communications and an adversary that can adaptively corrupt as many parties as it wishes, we present a new approach to solve the problem of concurrent deniable authentication within the framework of universally composable (UC) security. We formulate a definition of an ideal functionality for deniable authentication. Our constructions rely on a modification of the verifiably smooth projective hashing (VSPH) with projection key function by trapdoor commitment. Our protocols are forward deniable and UC security against adaptive adversaries in the common reference string model. A new approach implies that security is preserved under concurrent composition of an unbounded number of protocol executions; it implies non-malleability with respect to arbitrary protocols and more. The novelty of our schemes is the use of witness indistinguishable protocols and the security is based on the decisional composite residuosity (DCR) assumption. This new approach is practically relevant as it leads to more efficient protocols and security reductions.