Automatic Search of Truncated Impossible Differentials and Applications

Automatic Search of Truncated Impossible Differentials for Word-Oriented Block Ciphers (Full Version)

Impossible differential cryptanalysis is a powerful technique to recover the secret key of block ciphers by exploiting the fact that in block ciphers specific input and output differences are not compatible. This paper introduces a novel tool to search truncated impossible differentials for word-oriented block ciphers with bijective Sboxes. Our tool generalizes the earlier U-method and the UID-...

Automatic Search of Truncated Impossible Differentials for Word-Oriented Block Ciphers

New Automatic Search Tool for Impossible Differentials and Zero-Correlation Linear Approximations

Impossible differential cryptanalysis and zero-correlation linear cryptanalysis are two of the most useful cryptanalysis methods in the field of symmetric ciphers. Until now, there are several automatic search tools for impossible differentials such as U-method and UID-method, which are all independent of the non-linear S-boxes. Since the differential and linear properties can also contribute t...

Cryptanalysis of Reduced-Round Midori64 Block Cipher

Midori is a hardware-oriented lightweight block cipher designed by Banik et al. in ASIACRYPT 2015. It has two versions according to the state sizes, i.e. Midori64 and Midori128. In this paper, we explore the security of Midori64 against truncated differential and related-key differential attacks. By studying the compact representation of Midori64, we get the branching distribution properties of...

Search for Impossible Differential of E2

This paper studies the search for the impossible differentials of E2. We apply the Shrinking technique, the miss-in-the-middle technique, and a new search algorithm to E2. As a result, no impossible differential is found for E2 with more than 5 rounds. We conclude that E2 is secure against cryptanalysis using impossible differentials derived by the currently known techniques.