Preimage attack on step reduced hash function HAVAL
对缩减杂凑函数HAVAL的原根攻击

According to the order of the message words in HAVAL algorithm and the property of the function in the first pass, a preimage attack of the compression function from step 3 to step 122 was proposed by using "meeting-in-the-middle attack" and the exhaustive search method. The preimage attack on the 120-step reduced compression function was extended to the preimage attack on the 120-step reduced HAVAL by using "meeting-in-the-middle method" and the tree method respectively.