Claude Crépeau

1.1 Secure Function Evaluation (2008)

Claude Crépeau, George Savvides, Christian Schaffner

Abstract. The standard security definition of unconditional secure function evaluation, which is based on the ideal/real model paradigm, has the disadvantage of being overly complicated to work with...

Secure Multiparty Quantum Computation with (Only) a Strict Honest Majority (2008)

Ben-Or, Michael, Crépeau, Claude, Gottesman, Daniel, Hassidim, Avinatan, Smith, Adam

Secret sharing and multiparty computation (also called "secure function evaluation") are fundamental primitives in modern cryptography, allowing a group of mutually distrustful players to perform...

What is going on with Quantum Bit Commitment? (2007)

Claude Crépeau

Recent results in quantum physics indicate that Quantum Bit Commitment is impossible in a scenario where the participants have the full power of quantum mechanics to attack the protocol. This implies...

Réconciliation et Distillation publiques de secret (2007)

Claude Crépeau

2.46> Bob voudront obtenir par distillation publique un secret plus court f(X) sur lequel Eve n'a pas ou presque pas d'information. Cette situation, qui est une...

The Security of Quantum Bit Commitment Schemes (2007)

Gilles Brassard, Claude Crépeau, Dominic Mayers, Louis Salvail

Can quantum mechanics be harnessed to provide unconditionally secure bit commitment schemes and other cryptographic primitives beyond key distribution? We review the general impossibility proof of...

Quantum Oblivious Mutual Identification (2007)

Claude Crépeau, Louis Salvail

. We consider a situation where two parties, Alice and Bob, share a common secret string and would like to mutually check their knowledge of that string. We describe a simple and efficient protocol...

Verifiable Disclosure of Secrets and Applications (Abstract) (2007)

Claude Crépeau

A \Gamma 2 1 \Delta --Oblivious Bit Transfer protocol is a way for a party Rachel to get one bit from a pair b 0 ; b 1 that another party Sam offers her. The difficulty is that Sam should not find...

Efficient Reduction among Oblivious Transfer Protocols based on New Self-Intersecting Codes (2007)

Claude Crépeau, Miklós Sántha

A \Gamma 2 1 \Delta --OT 2 (one-out-of-two Bit Oblivious Transfer) is a technique by which a party S owning two secret bits b 0 ; b 1 , can transfer one of them b c to another party R, who chooses c....

Information-Theoretic Conditions for (2006)

Claude Crépeau, George Savvides, Christian Schaffner

The standard security definition of unconditional secure function evaluation, which is based on the ideal/real model paradigm, has the disadvantage of being overly complicated to work with in...

Information-Theoretic Conditions for Two-Party Secure Function Evaluation (2006)

Claude Crépeau, George Savvides, Christian Schaffner, Jürg Wullschleger

Abstract. The standard security definition of unconditional secure function evaluation, which is based on the ideal/real model paradigm, has the disadvantage of being overly complicated to work with...

Approximate Quantum ErrorCorrecting Codes and Secret Sharing Schemes (2005)

Claude Crépeau, Daniel Gottesman, Adam Smith

Abstract. It is a standard result in the theory of quantum error-correcting codes that no code of length n can fix more than n/4 arbitrary errors, regardless of the dimension of the coding and...

Efficient unconditional oblivious transfer from almost any noisy channel (2004)

Claude Crépeau, Kirill Morozov, Stefan Wolf

Abstract. Oblivious transfer (OT) is a cryptographic primitive of central importance, in particular in two- and multi-party computation. There exist various protocols for different variants of OT,...

Salvail,Computational Collapse of Quantum State with Application to Oblivious Transfer (2004)

Claude Crépeau, Paul Dumais, Dominic Mayers, Louis Salvail

Abstract. Quantum 2-party cryptography differs from its classical counterpart in at least one important way: Given blak-box access to a perfect commitment scheme there exists a secure 1−2 quantum...

Authentication of quantum messages (2002)

Howard Barnum, Claude Crépeau, Daniel Gottesman, Adam Smith

Authentication is a well-studied area of classical cryptography: a sender A and a receiver B sharing a classical secret key want to exchange a classical message with the guarantee that the message...

How to Convert the Flavor of a Quantum Bit Commitment (2001)

Claude Crépeau, Frédéric Légaré, Louis Salvail

Abstract. In this paper we show how to convert a statistically binding but computationally concealing quantum bit commitment scheme into a computationally binding but statistically concealing qbc...

Cryptologic Research Oblivious Transfers and Privacy Amplification ∗ (2001)

Gilles Brassard, Claude Crépeau, Stefan Wolf, Communicated Cynthia Dwork, Of G. Brassard, C. Crépeau, ...

Abstract. Oblivious transfer (OT) is an important primitive in cryptography. In chosen one-out-of-two string OT, a sender offers two strings, one of which the other party, called the receiver, can...

Defeating classical bit commitments with a quantum computer (1998)

Brassard, Gilles, Crépeau, Claude, Mayers, Dominic, Salvail, Louis

It has been recently shown by Mayers that no bit commitment scheme is secure if the participants have unlimited computational power and technology. However it was noticed that a secure protocol could...

The Security of quantum bit commitment schemes (1998)

Gilles Brassard, Dominic Mayers, Claude Crépeau, Louis Salvail

Can quantum mechanics be harnessed to provide unconditionally secure bit commitment schemes and other cryptographic primitives beyond key distribution? We review the general impossibility proof of...

A brief review on the impossibility of quantum bit commitment (1997)

Brassard, Gilles, Crépeau, Claude, Mayers, Dominic, Salvail, Louis

The desire to obtain an unconditionally secure bit commitment protocol in quantum cryptography was expressed for the first time thirteen years ago. Bit commitment is sufficient in quantum...

A brief review on the impossibility of quantum bit commitment." Los Alamos preprint archive quant-ph/9712023 (1997)

Gilles Brassard, Claude Crépeau, Dominic Mayers, Louis Salvail

The desire to obtain an unconditionally secure bit commitment protocol in quantum cryptography was expressed for the first time thirteen years ago. Bit commitment is sufficient in quantum...

Oblivious Transfers and Privacy Amplification (1997)

Gilles Brassard, Claude Crépeau, Claude Cr'epeau

. Assume A owns two secret k--bit strings. She is willing to disclose one of them to B, at his choosing, provided he does not learn anything about the other string. Conversely, B does not want A to...

A Brief Review on the Impossibility of Quantum Bit Commitment (1997)

Gilles Brassard, Claude Crépeau, Dominic Mayers, Louis Salvail

The desire to obtain an unconditionally secure bit commitment protocol in quantum cryptography was expressed for the first time thirteen years ago. Bit commitment is sufficient in quantum...

Cryptology Column - 25 Years of Quantum Cryptography (1996)

Gilles Brassard, Claude Crépeau, Claude Cr Epeau

Introduction The fates of SIGACT News and Quantum Cryptography are inseparably entangled. The exact date of Stephen Wiesner's invention of "conjugate coding" is unknown but it cannot...

Generalized Privacy Amplification (1995)

Charles H. Bennett, Gilles Brassard, Claude Crépeau, Ueli M. Maurer, Senior Member

. This paper provides a general treatment of privacy amplification by public discussion, a concept introduced by Bennett, Brassard and Robert for a special scenario. Privacy amplification is a...

Committed Oblivious Transfer and Private Multi-Party Computation (1995)

Claude Crépeau, Alain Tapp

. In this paper we present an efficient protocol for "Committed Oblivious Transfer" to perform oblivious transfer on committed bits: suppose Alice is committed to bits a0 and a1 and Bob is...

Generalized Privacy Amplification (1995)

Charles H. Bennett, Gilles Brassard, Claude Crépeau, Ueli M. Maurer, Senior Member

. This paper provides a general treatment of privacy amplification by public discussion, a concept introduced by Bennett, Brassard and Robert for a special scenario. Privacy amplification is a...

Oblivious Verification of Common String (1995)

Claude Crépeau, Louis Salvail

this paper is that of verifying knowledge of a common information for the purpose of identification. This common knowledge may be shared by a pair of people or several persons forming a select club....

Quantum Oblivious Transfer (1994)

Claude Crépeau

In a One-out-of-two Oblivious Transfer, a party Alice has two messages m 0 ; m 1 that she sends to another party Bob in such a way that he can decide to get either of them at his choosing but not...

Cryptographic Primitives and Quantum Theory (1993)

Claude Crépeau

This paper summarizes the current knowledge in the field of two-party cryptographic protocols devised from quantum systems. We introduce the reader to the notion of cryptographic protocols and...

Teleporting an Unknown Quantum State via Dual Classical and EPR Channels (1993)

Charles H. Bennett, Gilles Brassard, Claude Crépeau, Richard Jozsa, Asher Peres, William K. Wootters

An unknown quantum state jOEi can be disassembled into, then later reconstructed from, purely classical information and purely nonclassical EPR correlations. To do so the sender, "Alice,"...

Constant-Round Perfect Zero-Knowledge Computationally Convincing Protocols (1991)

Gilles Brassard, Claude Crépeau, Moti Yung

A perfect zero-knowledge 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...

Computationally convincing proofs of knowledge (Extended Abstract) (1991)

Gilles Brassard, Claude Crépeau, Sophie Laplante, Christian Léger

this paper, we give a more general definition, which is capable of taking into account very adversarial behaviour from the prover. We also prove that constant-round arguments for NP--

Weakening Security Assumptions and Oblivious Transfer (1990)

Claude Crépeau, Joe Kilian

) Claude Cr'epeau Department of Computer Science MIT Joe Kilian y Mathematics Department MIT 1 Introduction Our work is motivated by a recent trend in cryptographic research. Protocol problems...

Achieving Oblivious Transfer Using Weakened Security Assumptions (Extended Abstract) (1988)

Claude Crépeau, Joe Kilian

) Claude Cr'epeau Department of Computer Science MIT Joe Kilian y Mathematics Department MIT Abstract A useful paradigm in studying cryptographic scenarios is that of protocol minimalism. That...

A zero-knowledge Poker protocol that achieves confidentiality of the players' strategy or How to achieve an electronic Poker face (1986)

Claude Crépeau

This paper proposes a new poker protocol that allows players to keep secret their strategy. This protocol is an extension of the one given by Crepeau in [Cr]. The security will not be based on the...