Improving timing attack on RSA-CRT via error detection and correction strategy

Abstract

In timing attack, a class of side channel attack, the attacker attempts to break a cryptographic algorithm by timing the operations of a specific system. Several studies on different types of timing attacks have been published, but they are either theoretical or hard to put into practice. To improve the feasibility of timing attack, the current study proposes an improved timing attack scheme on RSA-CRT using t-test. Some similar types of timing attacks, such as BB-attack and Schindler’s attack, have been previously reported. However, none of these studies has applied these statistical methods with such efficiency, or has actually obtained complete recovery by attacking on RSA-CRT. The algorithm proposed in the present study provides an error detection mechanism and correction strategy that can detect and correct the erroneous decision of guessing qk. With an improvement timing attack on the RSA algorithm in OpenSSL, the 0–1gap is enlarged, the neighborhood size is reduced, and the precision of the decision is improved. Moreover, obtaining the factor q is practical, and even recovers a 1024-bit RSA key completely for an interprocess timing attack.