Linearly Homomorphic Encryption from DDH
CASTAGNOS, Guilhem
Lithe and fast algorithmic number theory [LFANT]
Institut de Mathématiques de Bordeaux [IMB]
Lithe and fast algorithmic number theory [LFANT]
Institut de Mathématiques de Bordeaux [IMB]
CASTAGNOS, Guilhem
Lithe and fast algorithmic number theory [LFANT]
Institut de Mathématiques de Bordeaux [IMB]
< Réduire
Lithe and fast algorithmic number theory [LFANT]
Institut de Mathématiques de Bordeaux [IMB]
Langue
en
Communication dans un congrès
Ce document a été publié dans
Lecture Notes in Computer Science, Lecture Notes in Computer Science, The Cryptographer's Track at the RSA Conference 2015, 2015-04-20, San Francisco. n° 9048
Résumé en anglais
We design a linearly homomorphic encryption scheme whose security relies on the hardness of the decisional Diffie-Hellman problem. Our approach requires some special features of the underlying group. In particular, its ...Lire la suite >
We design a linearly homomorphic encryption scheme whose security relies on the hardness of the decisional Diffie-Hellman problem. Our approach requires some special features of the underlying group. In particular, its order is unknown and it contains a subgroup in which the discrete logarithm problem is tractable. Therefore, our instantiation holds in the class group of a non maximal order of an imaginary quadratic field. Its algebraic structure makes it possible to obtain such a linearly homomorphic scheme whose message space is the whole set of integers modulo a prime p and which supports an unbounded number of additions modulo p from the ciphertexts. A notable difference with previous works is that, for the first time, the security does not depend on the hardness of the factorization of integers. As a consequence, under some conditions, the prime p can be scaled to fit the application needs.< Réduire
Mots clés en anglais
Linearly Homomorphic Encryption
Orders of Quadratic Fields
Diffie-Hellman Assumptions
Projet Européen
Lattices: algorithms and cryptography
Project ANR
Initiative d'excellence de l'Université de Bordeaux - ANR-10-IDEX-0003
Origine
Importé de halUnités de recherche