There is a algorithm that mixes bits for some hashes.
For example, using 32 bit integers
S = (e rightrotate 6) xor (e rightrotate 11) xor (e rightrotate 25)
Right Rotate, rotates the bits along the 32 bit area. It is much like a right shift but the bits appear on the other side such that rotating by a multiple of 32 will result in no change.
Xor, exclusive-ors the 32 bit result of the right rotates
The puzzle is to find ‘e’ if you have ‘S’