6 Round Improbable Differential Characteristic on M-PRESENT Using Undisturbed Bits

Undisturbed bit is one of the s-box weaknesses because it can use to construct improbable differential characteristic. That is as the first step of the improbable differential attack. In 2014, Tezcan succeeded in using the undisturbed bit to finding nine rounds of the improbable differential characteristic on the PRESENT with probability $\mathbf{p}^{\prime}=\mathbf{2}^{-\mathbf{9.29}}$. In 2017, Afifah and Sari Agustini H found another the improbable differential characteristic with higher probability consist of two characteristics with probability $\mathbf{p}^{\prime}=\mathbf{2}^{-\mathbf{8.91}}$ and a characteristic with probability $\mathbf{p}^{\prime}=\mathbf{2}^{-\mathbf{8.68}}$. In this research, s-box of the PRESENT has replaced with So of the I-PRESENT algorithm. The algorithm called as the M-PRESENT algorithm. Then we construct improbable differential characteristic to know the effect and comparison of the result using a different s-box. Based on the results of the research, we obtained the six rounds of the improbable differential characteristic on M-PRESENT with the highest probability of 2^−9.68 as many as eight characteristics. The urgency of this research is for consideration when we design an algorithm not to use s-box that has an undisturbed bit. If the probability of the improbable differential characteristic is high, then an algorithm can be said to be increasingly vulnerable to the improbable differential cryptanalysis.