Ghost key patterns with Equidistant Chosen Message attack on RSA-CRT

RSA is one of the most widely used public key algorithms, and the RSA-CRT variation is applied to improve efficiency of operations. Since Power analysis attacks were introduced, many researchers have studied not only power analysis attacks of RSA but also CRT specified attacks. Boer et al. [3] proposed a new analysis method for finding r = x mod p with equidistant chosen plaintexts. From the knowledge of r, we can compute a secret prime number p. As this method is based on equidistant messages, unlike general power analysis methods, it is called MRED (Modular reduction on equidistant data) power analysis or ECMPA (Equidistant Chosen Message Power Analysis). Since there are various novel characteristics in equidistant messages, there exist unusual properties of ghost keys that are not seen in general power attacks. In this paper, we describe unknown and interesting characteristics of ghost key patterns using real experiments.