Gérard Lallement (1935–2006)

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...

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...

Key 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...