Cryptanalysis of the Multilinear Map over the Integers

Jung Hee Cheon (1) , Kyoohyung Han (1) , Changmin Lee (1) , Hansol Ryu (1) , Damien Stehlé (2, 3)

1 SNU - Seoul National University [Seoul]
2 ARIC - Arithmetic and Computing
3 LIP - Laboratoire de l'Informatique du Parallélisme

We describe a polynomial-time cryptanalysis of the (approximate) multilinear map of Coron, Lepoint and Tibouchi (CLT). The attack relies on an adaptation of the so-called zeroizing attack against the Garg, Gentry and Halevi (GGH) candidate multilinear map. Zeroiz- ing is much more devastating for CLT than for GGH. In the case of GGH, it allows to break generalizations of the Decision Linear and Subgroup Membership problems from pairing-based cryptography. For CLT, this leads to a total break: all quantities meant to be kept secret can be efficiently and publicly recovered.

Domaines: Informatique [cs]

Jung Hee Cheon, Kyoohyung Han, Changmin Lee, Hansol Ryu, Damien Stehlé. Cryptanalysis of the Multilinear Map over the Integers. EUROCRYPT, 2015, Sofia, Bulgaria. ⟨hal-01240445⟩