Low-data complexity attacks on Camellia

Abstract

In this paper, we propose low-data complexity attacks on reduced-round Camellia. Our attacks are based on deterministic truncated differential characteristics exploiting properties of binaries matrices and differential properties of S-boxes of Camellia. Combining these with the structure of Camellia, we obtain low data complexity attacks on 4 to 7 rounds of Camellia. Surprisingly, 4 to 6 rounds attacks are feasible with only two chosen plaintexts and the attacks complexity becomes very practical by increasing a small amount of data.