Meet-in-the-Middle Preimage Attack on Round-reduced Areion256

\mathrmAreion is a family of highly-efficient permutations proposed by Isobe et al. in CHES 2023, which is designed for short-(Fixed)-input-length(SFIL) hash functions. In this paper, we study the preimage attack on \mathrmAreion-DM , an SFIL hash function based on \mathrmAreion permutation. Following the previous works of meet-in-the-middle (MITM) preimage attack, we proposed a new MILP-based automatic search model utilizing the linear combination of bytes from different chunks. We introduce a new attribute with new propagation rules, which could simplify the previous models. The new model reduces the number of variables and constraints of superposition technique. To search MTIM attacks with lower memory, we add new constraints to limit the size of the stored list. We have identified new preimage attacks on 6-round and 5-round \mathrmAreion256-DM . In the case of \mathrmAreion256 without the final swap, our finds reveal novel preimage attacks on 7-round and 5-round configurations, demonstrating lower memory complexities compared to previous results.