International Association
for Cryptologic Research

In this paper, we provide new quantum cryptanalysis results on $5$ rounds (balanced) Feistel schemes and on Benes schemes. More precisely, we give an attack on $5$ rounds Feistel schemes in $\Theta(2^{2n/3})$ quantum complexity and an attack on Benes schemes in $\Theta(2^{2n/3})$ quantum complexity, where $n$ is the number of bits of the internel random functions.