DES (06) - E bits selection table

??? L,R Block ??? ?????? ??????? ??????????????? L (32 bits) ??? ????????? ?????????? R (32 bits ) ??? key ?????????? function f(R,K) ?????????? ???????? ? ??? (?) ?????????? ?

??? (?)

?? algorithm ?? ??????? R (32 bits ) ??? E bits (48 bits) ?????????? ???????? ? E bits ?????????? R (32 bits) ??? bits ?????? ???????????? 48 bits ?????? ???????????? ??????????
E bits selection table ??? ??? (?) ?????????? ?

??? (?)

E bits selection table ???????????? 48 bits ?????? ?????????? ???? E bits (48 bits) ??? Key bits (48 bits) ??????? ?????? (Exclusive OR) ?????????? ???? ?????????? Key bits ????????? ?????? ????????? ????????? ?????????????? ????????????????? ??? ????????????? E bits ??? Key bits ????????????? function ?????????? ?????????? ?????????????? ?????????? E bits (48 bits) ??? Key (48 bits) ????????? 48 bits ??????? Binary code (0 or 1) ??? ?????????? (Exclusive OR) ? ?????????????? ??????????

(Exclusive OR)

x?y=z

0?0=0
0?1=1
1?0=1
1?1=0