Distinguishing Attack on SDDO-Based Block Cipher BMD-128

摘要

BMD-128 is a 128-bit block cipher with a 256-bit secret key and is based on switchable data-dependent operations. By using these operators, this algorithm was designed to ensure the high applicability in the transaction needing the change of session keys with high frequency. In this paper, we show that it is possible to distinguish between a 7-round reduced BMD-128 and a 128-bit random permutation under a related-key amplified boomerang attack scenario. This result is the first known cryptanalytic result on BMD-128.