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26
Proving in ZeroKnowledge that a Number is the Product of Two Safe Primes
, 1998
"... This paper presents the first efficient statistical zeroknowledge protocols to prove statements such as: A committed number is a pseudoprime. ..."
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Cited by 121 (13 self)
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This paper presents the first efficient statistical zeroknowledge protocols to prove statements such as: A committed number is a pseudoprime.
Proof Systems for General Statements about Discrete Logarithms
, 1997
"... Proof systems for knowledge of discrete logarithms are an important primitive in cryptography. We identify the basic underlying techniques, generalize these techniques to prove linear relations among discrete logarithms, and propose a notation for describing complex and general statements about know ..."
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Cited by 62 (5 self)
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Proof systems for knowledge of discrete logarithms are an important primitive in cryptography. We identify the basic underlying techniques, generalize these techniques to prove linear relations among discrete logarithms, and propose a notation for describing complex and general statements about knowledge of discrete logarithms. This notation leads directly to a method for constructing efficient proof systems of knowledge. 1 Introduction Many complex cryptographic systems, such as payment systems (e.g. see [1, 2, 4]) and voting schemes [11], are based on the difficulty of the discrete logarithm problem. These systems make use of various minimumdisclosure proofs of statements about discrete logarithms [13, 7, 6, 10]. Typical examples are efficient proofs of knowledge of a discrete logarithm which are based on Schnorr's digital signature scheme [18] and systems for proving the equality of two discrete logarithms, as used in [8]. The goal of this paper is to identify the basic techniques...
ConstantRound Perfect ZeroKnowledge Computationally Convincing Protocols
, 1991
"... A perfect zeroknowledge interactive protocol allows a prover to convince a verifier of the validity of a statement in a way that does not give the verifier any additional information [GMR,GMW]. Such protocols take place by the exchange of messages back and forth between the prover and the verifier. ..."
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Cited by 45 (5 self)
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A perfect zeroknowledge interactive protocol allows a prover to convince a verifier of the validity of a statement in a way that does not give the verifier any additional information [GMR,GMW]. Such protocols take place by the exchange of messages back and forth between the prover and the verifier. An important measure of efficiency for these protocols is the number of rounds in the interaction. In previously known perfect zeroknowledge protocols for statements concerning NPcomplete problems [BCC], at least k rounds were necessary in order to prevent one party from having a probability of undetected cheating greater than 2 \Gammak . In this paper, we give the first perfect zeroknowledge protocol that offers arbitrarily high security for any statement in NP with a constant number of rounds. The protocol is computationally convincing (rather than statistically convincing as would have been an interactive proofsystem in the sense of Goldwasser, Micali and Rackoff) because the ver...
Everything in NP can be argued in perfect zeroknowledge in a bounded number of rounds
, 1989
"... A perfect zeroknowledge interactive protocol allows a prover to convince a verifier of the validity of a statement in a way that does not give the verifier any additional information [GMR,GMW]. Such protocols take place by the exchange of messages back and forth between the prover and the verifier. ..."
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Cited by 34 (5 self)
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A perfect zeroknowledge interactive protocol allows a prover to convince a verifier of the validity of a statement in a way that does not give the verifier any additional information [GMR,GMW]. Such protocols take place by the exchange of messages back and forth between the prover and the verifier. An important measure of efficiency for these protocols is the number of rounds in the interaction. In previously known perfect zeroknowledge protocols for statements concerning NPcomplete problems [BCC], at least k rounds were necessary in order to prevent one party from having a probability of undetected cheating greater than 2 k . In this paper, we give the first perfect zeroknowledge protocol that offers arbitrarily high security for any statement in NP with a constant number of rounds (under the assumption that it is possible to find a prime p with known factorization of p 1 such that it is infeasible to compute discrete logarithms modulo p even for someone who knows the factors o...
Practical ZeroKnowledge Proofs: Giving Hints and Using Deficiencies
 JOURNAL OF CRYPTOLOGY
, 1994
"... New zeroknowledge proofs are given for some numbertheoretic problems. All of the problems are in NP, but the proofs given here are much more efficient than the previously known proofs. In addition, these proofs do not require the prover to be superpolynomial in power. A probabilistic polynomial t ..."
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Cited by 32 (0 self)
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New zeroknowledge proofs are given for some numbertheoretic problems. All of the problems are in NP, but the proofs given here are much more efficient than the previously known proofs. In addition, these proofs do not require the prover to be superpolynomial in power. A probabilistic polynomial time prover with the appropriate trapdoor knowledge is sufficient. The proofs are perfect or statistical zeroknowledge in all cases except one.
"Indirect Discourse Proofs": Achieving Efficient Fair OffLine ECash
, 1996
"... Cryptography has been instrumental in reducing the involvement of overhead third parties in protocols. For example; a digital signature scheme assures a recipient that a judge who is not present at message transmission will nevertheless approve the validity of the signature. Similarly, in offline ..."
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Cited by 25 (6 self)
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Cryptography has been instrumental in reducing the involvement of overhead third parties in protocols. For example; a digital signature scheme assures a recipient that a judge who is not present at message transmission will nevertheless approve the validity of the signature. Similarly, in offline electronic cash the bank (which is offline during a purchase) is assured that if a user double spends he will be traced. Here we suggest the notion of Indirect Discourse Proofs with which one can prove indirectly yet efficiently that a third party has a certain future capability (i.e., assure Trustees can trace). The efficient proofs presented here employ algebraic properties of exponentiation (or functions of similar homomorphic nature). Employing this idea we present the concept of "Fair OffLine eCash" (FOLC) system which enables tracing protocols for identifying either the coin or its owner. Recently, the need to trace and identify coins with owners/withdrawals was identified (to av...
How to Prove All NP Statements in ZeroKnowledge and a Methodology of Cryptographic Protocol Design (Extended Abstract)
 PROC. OF CRYPTO 1986, THE 6TH ANN. INTL. CRYPTOLOGY CONF., VOLUME 263 OF LECTURE NOTES IN COMPUTER SCIENCE
, 1998
"... ..."
On the fly authentication and signature schemes based on groups of unknown order
 Journal of Cryptology
, 2006
"... 3 E'cole normale supe'rieure, De'partement d'informatique 45 rue d'Ulm, F75230 Paris Cedex 05, ..."
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Cited by 18 (1 self)
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3 E'cole normale supe'rieure, De'partement d'informatique 45 rue d'Ulm, F75230 Paris Cedex 05,
Attacking and fixing helios: An analysis of ballot secrecy
, 2010
"... Helios 2.0 is an opensource webbased endtoend verifiable electronic voting system, suitable for use in lowcoercion environments. In this paper, we analyse ballot secrecy and discover a vulnerability which allows an adversary to compromise the privacy of voters. This vulnerability has been success ..."
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Cited by 17 (6 self)
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Helios 2.0 is an opensource webbased endtoend verifiable electronic voting system, suitable for use in lowcoercion environments. In this paper, we analyse ballot secrecy and discover a vulnerability which allows an adversary to compromise the privacy of voters. This vulnerability has been successfully exploited to break privacy in a mock election using the current Helios implementation. Moreover, the feasibility of an attack is considered in the context of French legislative elections and, based upon our findings, we believe it constitutes a real threat to ballot secrecy in such settings. Finally, we present a fix and show that our solution satisfies a formal definition of ballot secrecy using the applied pi calculus.