Changes

Note that the attack attemps to recover the [[wikipedia:File:DES-key-schedule.png|first round key]], which only has 48bits ([[wikipedia:File:DES-f-function.png|8 s-box boxes x 6 bits each]]), while the original key has 56 significant bits (64 if we count the parity bits that are irrelevant). So, if we map the first round key, obtained after the attack, to the original key (you can use the provided DES Key Schedule Tool to do it), there will still be 8 bits missing (256 combinations).