Post‑scriptum sur Gérard Althabe

Gérard Maze and Lorenz

Cryptography based on Semigroup Actions ∗ Gérard Maze

A generalization of the original Diffie-Hellman key exchange in (Z/pZ) found a new depth when Miller [27] and Koblitz [16] suggested that such a protocol could be used with the group over an elliptic curve. In this paper, we propose a further vast generalization where abelian semigroups act on finite sets. We define a Diffie-Hellman key exchange in this setting and we illustrate how to build in...

Postscriptum - A Personal Point of View

Impressed by the elegance and simplicity of the Popov frequency criterion and the concept of hyperstability, I have joined in October 1967 (for one year) the group of V.M. Popov at the Energy Institute of the Romanian Academy with the objective to apply the Popov theory to adaptive systems and real-time identification. From the interpretation of the Popov stability criterion in terms of an equi...

6 Dynamics of trap models Gérard

3 The one-dimensional trap model 9 3.1 The Fontes-Isopi-Newman singular diffusion . . . . . . . . . . . . . . . . 10 3.2 The scaling limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.3 Aging results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.4 Subaging results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.5 Behaviour of t...

Identities , forgeries and disguises Gérard Chollet and

The preservation of your identity could become a major concern. In many situations, you need to claim an identity and this claim needs to be verified somehow. The technology called biometrics may help. But, what if a deliberate impostor claims your identity? Will this forgery be always detected? Biometric identity verification is imperfect. This paper reviews some of the techniques that a delib...