Impossible Differential Cryptanalysis of Surge

Abstract

In 2018, Li Lang et al. proposed a new lightweight block cipher which is called Surge. Its block size is 64-bit, and the length of key size is 64/80/128-bit, respectively. They also proved that the cipher has good performance on security and effectively resists on differential attack, linear attack and algebraic attack. In this paper, some 4-round impossible differentials are constructed with the miss-in-the-middle method. Furthermore, 6-round impossible differential attacks are proposed on Surge- 64/Surge-80/Surge-128 algorithms based on the 4-round impossible differentials. The data complexity of the attack is 238/239/239.5 chosen plaintexts, the time complexity is 251.4/251.7/260.9 6-round encryptions, and the storage complexity is 240/240.1/249 storage units. This is the first time to make the impossible differential cryptanalysis for Surge.