In this paper, we study the soundness amplification by repetition of cryptographic protocols. As a tool, we use the Chernoff Information. We specify the number of attempts or samples required to distinguish two distributions efficiently in various protocol ...
Block ciphers probably figure in the list of the most important cryptographic primitives. Although they are used for many different purposes, their essential goal is to ensure confidentiality. This thesis is concerned by their quantitative security, that i ...
Cryptography often meets the problem of distinguishing distributions. In this paper we review techniques from hypothesis testing to express the advantage of the best distinguisher limited to a given number of samples. We link it with the Chernoff informati ...
In this paper we re-visit distinguishing attacks. We show how to generalize the notion of linear distinguisher to arbitrary sets. Our thesis is that our generalization is the most natural one. We compare it with the one by Granboulan et al. from FSE'06 by ...
We introduce C, a practical provably secure block cipher with a slow key schedule. C is based on the same structure as AES but uses independent random substitution boxes instead of a fixed one. Its key schedule is based on the Blum-Blum-Shub pseudo-random ...
We introduce KFC, a block cipher based on a three round Feistel scheme. Each of the three round functions has an SPN-like structure for which we can either compute or bound the advantage of the best d-limited adaptive distinguisher, for any value of d. Usi ...
In this paper we study the substitution-permutation network (SPN) on which Rijndael is based. We introduce Rijndael*, a SPN identical to Rijndael except that fixed S-boxes are replaced by random and independent permutations. We prove that this construction ...