A Chosen-Plaintext Method of CPA on SM4 Block Cipher

In this paper, we will present a chosen-plaintext method of CPA on SM4 block cipher. This attack consists of a chosen-plaintext method and a transformed CPA attack. The chosen-plaintext method is used to decrease the computation complexity to guess the round register value and the transformed CPA attack is introduced to improve the effect of CPA attack. We accomplished hardware implement on Sasebo-Gii and power analysis, whose result proved that it takes 5000 traces to recover the key successfully by our method, while the normal CPA method needs 270000 traces.