A fast correlation attack on LILI-128

In English In this paper we demonstrate a fast correlation attack on the recently proposed stream cipher LILI-128. The attack has complexity around 2(71) bit operations assuming a received sequence of length around 2(30) bits and a precomputation phase of complexity 2(79) table lookups. This complexity is significantly lower than 2(112), which was conjectured by the inventors of LILI-128 to be a lower bound on the complexity of any attack.