CryptoDB

Jean-Jacques Quisquater

Publications

Year
Venue
Title
2012
ASIACRYPT
2011
JOFC
2009
EPRINT
A multi-set (MS) is a set where an element can occur more than once. MS hash functions (MSHFs) map MSs of arbitrary cardinality to fixed-length strings. This paper introduces a new RSA-based MSHF. The new function is efficient and produces small hashes. We prove that the proposed MSHF is collision-resistant under the assumption of unforgeability of deterministic RSA signatures. In many practical applications, programmers need to compare two (unordered) sets of integers. A trivial solution consists in sorting both sets ($\mathcal{O}(n \log n)$) and comparing them linearly. We show how MS hash functions can be turned into a linear-time, constant-space integer set equality test.
2008
FSE
2008
FSE
2008
EPRINT
Collisions in the LPS cryptographic hash function of Charles, Goren and Lauter have been found by Zémor and Tillich, but it was not clear whether computing preimages was also easy for this hash function. We present a probabilistic polynomial time algorithm solving this problem. Subsequently, we study the Morgenstern hash, an interesting variant of LPS hash, and break this function as well. Our attacks build upon the ideas of Zémor and Tillich but are not straightforward extensions of it. Finally, we discuss fixes for the Morgenstern hash function and other applications of our results.
2008
EPRINT
We propose to apply an information theoretic metric to the evaluation of side-channel resistant logic styles. Due to the long design and development time required for the physical evaluation of such hardware countermeasures, our analysis is based on simulations. Although they do not aim to replace the need of actual measurements, we show that simulations can be used as a meaningful first step in the validation chain of a cryptographic product. For illustration purposes, we apply our methodology to gate-level simulations of different logic styles and stress that it allows a significant improvement of the previously considered evaluation methods. In particular, our results allow putting forward the respective strengths and weaknesses of actual countermeasures and determining to which extent they can practically lead to secure implementations (with respect to a noise parameter), if adversaries were provided with simulation-based side-channel traces. Most importantly, the proposed methodology can be straightforwardly adapted to adversaries provided with any other kind of leakage traces (including physical ones).
2008
EPRINT
In wireless roaming a mobile device obtains a service from some foreign network while being registered for the similar service at its own home network. However, recent proposals try to keep the service provider role behind the home network and let the foreign network create a tunnel connection through which all service requests of the mobile device are sent to and answered directly by the home network. Such Wireless Roaming via Tunnels (WRT) offers several (security) benefits but states also new security challenges on authentication and key establishment, as the goal is not only to protect the end-to-end communication between the tunnel peers but also the tunnel itself. In this paper we formally specify mutual authentication and key establishment goals for WRT and propose an efficient and provably secure protocol that can be used to secure such roaming session. Additionally, we describe some modular protocol extensions to address resistance against DoS attacks, anonymity of the mobile device and unlinkability of its roaming sessions, as well as the accounting claims of the foreign network in commercial scenarios.
2008
PKC
2007
CHES
2007
CHES
2007
PKC
2007
EPRINT
In this paper, we consider a recently introduced framework that investigates physically observable implementations from a theoretical point of view. The model allows quantifying the effect of practically relevant leakage functions with a combination of security and information theoretic metrics. More specifically, we apply our evaluation methodology to an exemplary block cipher. We first consider a Hamming weight leakage function and evaluate the efficiency of two commonly investigated countermeasures, namely noise addition and masking. Then, we show that the proposed methodology allows capturing certain non-trivial intuitions, e.g. about the respective effectiveness of these countermeasures. Finally, we justify the need of combined metrics for the evaluation, comparison and understanding of side-channel attacks.
2006
CHES
2006
CHES
2006
PKC
2005
ASIACRYPT
2005
CHES
2004
FSE
2004
PKC
2004
EPRINT
This paper first positively answers the previously open question of whether it was possible to obtain an optimal security reduction for an identity based signature (IBS) under a reasonable computational assumption. We revisit the Sakai-Ogishi-Kasahara IBS that was recently proven secure by Bellare, Namprempre and Neven through a general framework applying to a large family of schemes. We show that their modified SOK-IBS scheme can be viewed as a one-level instantiation of Gentry and Silverberg's alternative hierarchical IBS the exact security of which was never considered before. We also show that this signature is as secure as the one-more Diffie-Hellman problem. As an application, we propose a modification of Boyen's "Swiss Army Knife" identity based signature encryption (IBSE) that presents better security reductions and satisfies the same strong security requirements with a similar efficiency.
2004
EPRINT
In this paper, we present a new parallel architecture to avoid side-channel analyses such as: timing attack, simple/differential power analysis, fault induction attack and simple/differential electromagnetic analysis. We use a Montgomery Multiplication based on Residue Number Systems. Thanks to RNS, we develop a design able to perform an RSA signature in parallel on a set of identical and independent coprocessors. Of independent interest, we propose a new DPA countermeasure in the framework of RNS. It is only (slightly) memory consuming (1.5 KBytes). Finally, we synthesized our new architecture on FPGA and it presents promising performance results. Even if our aim is to sketch a secure architecture, the RSA signature is performed in less than 160 ms, with competitive hardware resources. To our knowledge, this is the first proposal of an architecture counteracting electromagnetic analysis apart from hardware countermeasures reducing electromagnetic radiations.
2003
CHES
2003
CHES
2003
CHES
2003
EUROCRYPT
2003
EPRINT
We present a new identity based scheme based on pairings over elliptic curves. It combines the functionalities of signature and encryption and is provably secure in the random oracle model. We compare it with Malone-Lee's one from security and efficiency points of view. We give a formal proof of semantical security under the Decisional Bilinear Diffie-Hellman assumption for this new scheme and we show how to devise other provably secure schemes that produce even shorter ciphertexts.
2003
EPRINT
In this paper we describe an integral distinguisher over 2 rounds of Safer++. It allows a practical attack against 3 rounds of Safer++128, as well as attacks on 4 rounds of Safer++128 and Safer++256, under the chosen-plaintext hypothesis. These results achieve much lower complexity than the currently known best attacks on Safer++, namely weak-key linear cryptanalysis by Nakahara. As a side result, we prove that the byte-branch number of the linear transform of Safer++ is 5. We also discuss a way for further research in order to extend integral cryptanalysis.
2003
EPRINT
In this paper, we give a first example of identity based undeniable signature using pairings over elliptic curves. We extend to the identity based setting the security model for the notions of invisibility and anonymity given by Galbraith and Mao in 2003 and we prove that our scheme is existentially unforgeable under the Bilinear Diffie-Hellman assumption in the random oracle model. We also prove that it has the invisibility property under the Decisional Bilinear Diffie-Hellman assumption and we discuss about the efficiency of the scheme.
2002
CHES
2002
CHES
2002
CHES
2001
CHES
2000
CHES
1999
JOFC
1998
ASIACRYPT
1995
CRYPTO
1994
ASIACRYPT
1994
CRYPTO
1991
JOFC
1990
CRYPTO
1990
EUROCRYPT
1989
CRYPTO
1989
CRYPTO
1989
CRYPTO
1989
EUROCRYPT
1989
EUROCRYPT
1989
EUROCRYPT
1988
CRYPTO
1988
EUROCRYPT
1987
CRYPTO
1987
CRYPTO
1987
CRYPTO
1986
CRYPTO
1986
EUROCRYPT
1985
CRYPTO
1984
CRYPTO
1984
CRYPTO
1984
EUROCRYPT
1983
CRYPTO

Program Committees

CHES 2009
CHES 2008
Asiacrypt 2005
CHES 2004 (Program chair)
PKC 2002
CHES 2001
PKC 2000
CHES 2000
Crypto 1999
Eurocrypt 1999
CHES 1999
Crypto 1998
Eurocrypt 1995
Crypto 1995
Eurocrypt 1989 (Program chair)
Eurocrypt 1987
Eurocrypt 1984