Pierre-Louis Cayrel

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Ring signatures were introduced by Rivest, Shamir, and Tauman in 2001. These signatures allow a signer to anonymously authenticate a message on behalf of a group of his choice. This concept was then extended by Bresson, Stern, and Szydlo into <i>t</i>-out-of-<i>N</i> (threshold) ring signatures in 2002. We propose in this article a generalization of Stern's(More)
The McEliece cryptosystem is one of the oldest public-key cryptosystem ever designated. It is also the first public-key cryptosystem based on linear error-correcting codes. The main advantage of the McEliece cryptosystem is to have a very fast encryption and decryption functions but suffers from a major drawback. It requires a very large public key which(More)
Courtois-Finiasz-Sendrier (CFS) digital signatures critically depend on the ability to efficiently find a decodable syndrome by random sampling the syndrome space, previously restricting the class of codes upon which they could be instantiated to generic binary Goppa codes. In this paper we show how to construct t-error correcting quasi-dyadic codes where(More)
At CRYPTO’93, Stern proposed a 3-pass code-based identification scheme with a cheating probability of 2/3. In this paper, we propose a 5-pass code-based protocol with a lower communication complexity, allowing an impersonator to succeed with only a probability of 1/2. Furthermore, we propose to use double-circulant construction in order to dramatically(More)
In this article, we propose a new lattice-based threshold ring signature scheme, modifying Aguilar’s code-based solution to use the short integer solution (SIS) problem as security assumption, instead of the syndrome decoding (SD) problem. By applying the CLRS identification scheme, we are also able to have a performance gain as result of the reduction in(More)
Zero-knowledge identification schemes solve the problem of authenticating one party to another via an insecure channel without disclosing any additional information that might be used by an impersonator. In this paper we propose a scheme whose security relies on the existence of a commitment scheme and on the hardness of worst-case lattice problems. We(More)
Hash functions are one of the most important cryptographic primitives. Some of the currently employed hash functions like SHA-1 or MD5 are considered broken today. Therefore, in 2007 the US National Institute of Standards and Technology announced a competition for a new family of hash functions. Keccak is one of the five final candidates to be chosen as(More)
In this paper we present efficient implementations of McEliece variants using quasi-dyadic codes. We provide secure parameters for a classical McEliece encryption scheme based on quasi-dyadic generalized Srivastava codes, and successively convert our scheme to a CCA2-secure protocol in the random oracle model applying the Fujisaki-Okamoto transform. In(More)
In this paper, we propose a new identity-based authentication (and signature) scheme based on error-correcting codes. This scheme is up to date the first identity-based scheme not based on number theory. The scheme combines two well known code-based schemes: the signature scheme of Courtois, Finiasz and Sendrier and the zero-knowledge authentication scheme(More)