The Pushdown Attack on AES

Abstract

We present a new idea on chosen plaintext cryptanalysis, where we can bypass some of the cipher's encryption rounds at its beginning. To illustrate this idea, we developed the Pushdown attack. This attack can increase the strength of some chosen plaintext attacks. We applied the Pushdown attack on AES and was able to achieve a 6-round attack that requires only 2$^{11}$ chosen plaintexts, this reduces the chosen plaintexts needed by the Square attack with a factor of 2$^{21}$.