用vb实现DES加解密算法(三)--解密(5) For i = 0 To 47 K2(i) = C_D(PC_2(i)) Next '***************************************************K3 '生成C3,D3 For i = 0 To 25 C3(i) = C2(i + Lsi(3)) D3(i) = D2(i + Lsi(3)) Next C3(26) = C2(0) D3(26) = D2(0) C3(27) = C2(1) D3(27) = D2(1) '组合C3,D3成C_D For i = 0 To 27 C_D(i) = C3(i) C_D(i + 28) = D3(i) Next 'PC_2转换,生成K3 For i = 0 To 47 K3(i) = C_D(PC_2(i)) Next '***************************************************K4 '生成C4,D4 For i = 0 To 25 C4(i) = C3(i + Lsi(4)) D4(i) = D3(i + Lsi(4)) Next C4(26) = C3(0) D4(26) = D3(0) C4(27) = C3(1) D4(27) = D3(1) '组合C4,D4成C_D For i = 0 To 27 C_D(i) = C4(i) C_D(i + 28) = D4(i) Next 'PC_2转换,生成K4 For i = 0 To 47 K4(i) = C_D(PC_2(i)) Next '***************************************************K5