Improved Attacks on Reduced-Round Camellia-128/192/256

Camellia is a widely used block cipher, which has been selected as an international standard by ISO/IEC. In this paper, we consider a new family of differentials of round-reduced Camellia-128 depending on different key subsets. There are totally 224 key subsets corresponding to 224 types of 8-round differentials, which cover a fraction of 1− 1/2 of the keyspace. And each type of 8-round differential consists of 2 differentials. Combining with the multiple differential attack techniques, we give the key-dependent multiple differential attack on 10-round Camellia-128 with data complexity 2 and time complexity 2. Furthermore, we propose a 7-round property for Camellia-192 and an 8-round property for Camellia-256, and then mount the meet-in-the-middle attacks on 12-round Camellia-192 and 13-round Camellia-256, with complexity of 2 encryptions and 2 encryptions, respectively. All these attacks start from the first round in a single key setting.