Yea, I was thinking the same, but then I thought that there may be some smart way to rearrange some of the SHA-256 algorithm to change simple bit shifts, exclusive-ors and addition into more complex multiplies, maybe by carrying out two or three operations at once. But it would require a deep knowledge of the SHA-256 algorithm and binary maths. Something along the lines of way that Laplace can be used to solve differential equations by transferring everything into the S-domain, solve with addition and subtraction and then transfer back for the answer.