599 résultats
-
Soutenance de thèse (exceptionnellement mercredi à 13h30 en salle Petri-Turing à l'IRISA): Algorithmes d'algèbre linéaire pour la cryptographie
Orateur : Claire Delaplace - Université Rennes 1
Dans cette thèse, nous discutons d’aspects algorithmiques de trois différents problèmes, en lien avec la cryptographie. La première partie est consacrée à l’algèbre linéaire creuse. Nous y présentons un nouvel algorithme de pivot de Gauss pour matrices creuses à coefficients exacts, ainsi qu’une nouvelle heuristique de selection de pivots, qui rend l’entière procédure particulièrement efficace[…] -
On the design and implementation of scalar multiplication algorithms
Orateur : Koray Karabina - Florida Atlantic University
Diffie-Hellman type key exchange protocols and standardized digital signature algorithms all benefit from efficient design and secure implementation of group exponentiation algorithms. This talk will focus on elliptic curve groups and scalar multiplication algorithms derived from differential addition chains. First, I will give a survey of algorithms, and then I will present some recent[…] -
Learning Strikes Again: the Case of the DRS Signature Scheme
Orateur : Yu Yang - CWI Amsterdam
Lattice signature schemes generally require particular care when it comes to preventing secret information from leaking through signature transcript. For example, the Goldreich-Goldwasser-Halevi (GGH) signature scheme and the NTRUSign scheme were completely broken by the parallelepiped-learning attack of Nguyen and Regev (Eurocrypt 2006). Several heuristic countermeasures were also shown[…] -
Practical Strategy-Resistant Privacy-Preserving Elections
Orateur : Quentin Santos - Orange
Recent advances in cryptography promise to let us run com- plex algorithms in the encrypted domain. However, these results are still mostly theoretical since the running times are still much larger than their equivalents in the plaintext domain. In this context, Majority Judgment is a recent proposal for a new voting system with several interesting practical advantages, but which implies a more[…] -
Schindler-Itoh/Wiemers revisited: recovering full RSA/ECC private key from noisy side-channel observations
Orateur : Victor Lomné et Thomas Roche
Side-channel attacks on public-key cryptography (i.e. modular exponentiation for RSA or scalar multiplication for ECC) often boils down to distinguishing the 0s from the 1s in the binary representation of the secret exponent (resp. secret scalar).When state-of-the-art countermeasures are implemented, this detection must be errorless: thanks to masking techniques, erroneous masked exponents (resp.[…] -
Zero-Knowledge Argument for Matrix-Vector Relations and Lattice-Based Group Encryption
Orateur : Fabrice Mouhartem - ENS Lyon
Group encryption (GE) is the natural encryption analogue of group signatures in that it allows verifiably encrypting messages for some anonymous member of a group while providing evidence that the receiver is a properly certified group member. Should the need arise, an opening authority is capable of identifying the receiver of any ciphertext. As intro- duced by Kiayias, Tsiounis and Yung […]