A Horizontal Attack on SM9 Signature Generation

In this paper, we will present a horizontal attack on SM9 signature generation. The horizontal attack can make use of the information from multiple locations on one curve of SM9 signature generation to exploit the secret key. Since only one curve is needed in this attack, the conventional countermeasures like message blinding and key randomization would not work. We accomplished the security evaluation of SM9 signature generation on Sasebo-GII. The experiment results show that a vulnerable realization could leak the information of all key bits.