Fault Attack on an Improved CRT-RSA Algorithm with the Modulus Chaining Method

Fanyu Kong, Dashui Zhou, Yali Jiang, Jianwei Shang, Jia Yu

Abstract: S. Lee, D. Choi and Y. Choi proposed an improved countermeasure algorithm of RSA cryptosystem with Chinese Remainder Theorem to prevent fault attack. In this paper, we introduce new fault attacks on their countermeasure algorithm. Our analysis shows that the attacker can obtain an erroneous signature by injecting some faults during the RSA signing computation. Thus the attacker can recover the RSA private key and their countermeasure algorithm cannot resist the fault attack.