Some rocket science, some dice, a few weeks of calm and quiet, a few cups of coffee and finally an HD wallet to generate 256 keys and then masking each key with 0s to place each key in a certain bit range.
Like :
9845224217be692ed430097d85a368999c01f3d14e5cf30c3b0ce72921e9d0cf

Replace the strike through characters with 0s and good to go.