Low-Data Cryptanalysis On SKINNY Block Cipher. (2nd February 2022) - Hua, Jialiang
Abstract: At CRYPTO 2021, Dong et al. proposed an automatic method of Meet-in-the-Middle (MITM) key-recovery attacks. In this paper, we further extend it to a new automatic model which can be used to find low-data complexity attacks. With the help of the automatic model, we propose MITM attacks against reduced-round versions of all the six members of the SKINNY family with extremely low-data complexity. More precisely, we present MITM attacks against 19-round SKINNY -$n$ -$3n$, 15-round SKINNY -$n$ -$2n$, 11-round SKINNY -$n$ -$n$ with three, two, one plaintext-ciphertext pairs, separately. In addition, we can attack two more rounds and three more rounds with no more than $2^8$ and $2^{32}$ data complexity, respectively.