Zodiac is a block cipher algorithm and it supports 3 master key lengths which are called Zodiac-128, Zodiac-192 and Zodiac-256. The security of Zodiac algorithm was evaluated by using zero-correlation linear cryptanalysis. Firstly, 10-round zero-correlation linear approximations of Zodiac algorithm were constructed according to the structural characteristics of the algorithm. Then, the multidimensional zero-correlation linear cryptanalysis on 16-round Zodiac-192 was conducted. The analysis results show that 19-byte keys were restored totally in the process of attack, the data complexity was about 2 ^124.40 known ciphertexts and the computational complexity was 2 ^181.58 encryptions of 16-round. Thus the Zodiac-192 algorithm with the 192-bit key of 16 rounds (full rounds) is not immune to the zero-correlation linear cryptanalysis.

At present, the safety analysis of SNAKE algorithm is mainly about interpolation attack and impossible differential attack. The paper evaluated the security of SNAKE(2) block cipher against integral attack. Based on the idea of higher-order integral attack, an 8-round distinguisher was designed. Using the distinguisher, integral attacks were made on 9/10 round SNAKE(2) block cipher. The attack results show that the 10-round SNAKE(2) block cipher is not immune to integral attack.