Description
Lattice-based cryptography is one of the major line of research to build post-quantum public key primitives. In this thesis, we discuss about digital signatures constructions and their implementation. We first describe a Fiat-Shamir transformation from an identification scheme using rejection sampling to a digital signature secure in the random oracle model. Then we describe an identity-based encryption scheme and we prove its security in the standard model. An identity-based encryption scheme is like a classical public key where the public key is the identity of a user such as its email address or its social security number.<br/> A user contacts a third trusted party to get a secret key associated to its identity. In our construction, a secret key consists essentially in a signature of the identity of the user. We also describe this underlying digital signature scheme associated to our identity based encryption scheme.<br/> Finally, we present implementation results of these two schemes and how we choose concrete parameters.<br/> lien: rien
Prochains exposés
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Dual attacks in code-based (and lattice-based) cryptography
Orateur : Charles Meyer-Hilfiger - Inria Rennes
The hardness of the decoding problem and its generalization, the learning with errors problem, are respectively at the heart of the security of the Post-Quantum code-based scheme HQC and the lattice-based scheme Kyber. Both schemes are to be/now NIST standards. These problems have been actively studied for decades, and the complexity of the state-of-the-art algorithms to solve them is crucially[…]-
Cryptography
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Lie algebras and the security of cryptosystems based on classical varieties in disguise
Orateur : Mingjie Chen - KU Leuven
In 2006, de Graaf et al. proposed a strategy based on Lie algebras for finding a linear transformation in the projective linear group that connects two linearly equivalent projective varieties defined over the rational numbers. Their method succeeds for several families of “classical” varieties, such as Veronese varieties, which are known to have large automorphism groups. In this talk, we[…]-
Cryptography
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