Multiple Related-Key Diff erential Attacks on Pure DDP-Based Cipher

摘要

By constructing three types of related-key differential characteristics, we present three corresponding related-key differential attacks on the cipher. As the inde-pendence of the characteristics, we could recover 64 bits of the cipher’s m aster key with 258.6 chosen plain-texts, 258.8 full-round DDP-64 encryptions and 212.8 bits of storage re-sources. To break the cipher, we only need to implement an exhaustive search for the rest 64 bits of the m aster key.