DES (10) - Iteration ????????????????? PC-2

?? PC-1 ?? 64bits ??? 56 bits ????????????????? ???? 64bits ??? 8bits ??????????????? ???????????? 8,16,24,32,40,48,56 ??? 64 ???????? bits ??? ??????????
???? 56bits ????? C ??? D ??????? ???????? ??? 28bits (1-28�) ?? C ???????? ?????? 28bits (29-56) ?? D ?????????? C0 ??? D0 ???? ?????? Left shift (?????????? ?????????????) ??????????? ?????????? C ??? D ????? left shift 16 rounds ????????? Iterarion ???? ??????? ???????? ?????????????????

???????? C0 ??? D0 ????? left shift ?? 1 ?????????? ?????? C0 ??? 1st ????? bit ?? 32nd ??????? ???????????????? ???? 32nd ? 31st ????????????????????? D0 ???? ????????? ?????????? C0 ??? D0 ??? shifted ??????????? C1 (28 bits) ??? D1 (28 bits) ?????????????? ???? 56bits ??? Permuted choice -2 (PC-2) ?? ???????????????? key1 ????? 48bits ??????? ???(??) ???????????

???(??)

?????????? Key1 (48btis) ?? function ????? E-bits (48bits) ??? XOR ??????????? ?????????? ??????????? C1 ??? D1 ??????????? key algorithm ???????? left shift ???? ??? ??????? ?????????? C2 ??? D2 ?????????? ????? ?????????????? key 16 round ????????????