Bài tập an toàn thông tin DES

1. Bài tập tổng hợp về mã hóa DES
Cho bảng dữ liệu và khóa K như bên dưới, tìm bản tin đầu ra sau khi lặp 2 vòng.
1 1 1 0 1 1 0 0
1 0 0 0 0 1 1 1
0 1 0 1 0 1 0 1
1 1 1 0 1 0 0 1
1 0 1 0 1 1 0 0
0 1 1 1 0 1 1 0
0 1 0 0 0 0 1 0
1 0 1 1 1 1 0 0
Khối dữ liệu đầu vào
0 0 1 0 1 1 0 0
1 0 1 0 0 1 1 1
0 1 0 1 0 1 0 0
0 1 1 1 1 0 0 1
1 0 1 0 1 1 0 1
1 0 1 1 0 1 1 0
1 1 0 0 1 0 1 1
1 0 1 0 1 0 0 0
Khóa K

2. 0 1 1 0 1 1 0 1
1 0 1 0 0 1 0 0
1 0 1 1 0 1 1 1
0 0 0 0 1 1 1 0
1 0 0 1 1 0 1 1
1 0 1 1 1 0 0 1
1 0 0 1 1 0 0 1
0 1 1 0 0 0 1 0
0 1 1 0 1 1 0 1
1 0 1 0 0 1 0 0
1 0 1 1 0 1 1 1
0 0 0 0 1 1 1 0
1 0 0 1 1 0 1 1
1 0 1 1 1 0 0 1
1 0 0 1 1 0 0 1
0 1 1 0 0 0 1 0
L
0
R
0

3. 0 1 0 0 1 1
1 1 0 1 1 1
1 1 0 1 1 1
1 1 0 0 1 1
1 1 0 0 1 1
1 1 0 0 1 0
1 0 1 0 0 0
0 0 0 1 0 1
E table

4. 0 0 1 0 1 1 0 0
1 0 1 0 0 1 1 1
0 1 0 1 0 1 0 0
0 1 1 1 1 0 0 1
1 0 1 0 1 1 0 1
1 0 1 1 0 1 1 0
1 1 0 0 1 0 1 1
1 0 1 0 1 0 0 0
1 2 3 4 5 6 7 8
9
17
25
33
41
49
57
1 1 1 1 0 0 1
0 0 1 0 0 1 1
0 0 1 0 1 1 1
0 1 1 0 0 1 0
0 1 1 0 0 0 1
0 0 0 1 1 0 1
1 1 1 1 0 1 1
0 0 1 1 1 0 0

5. 1 1 1 1 0 0 1
0 0 1 0 0 1 1
0 0 1 0 1 1 1
0 1 1 0 0 1 0
Left
0 1 1 0 0 0 1
0 0 0 1 1 0 1
1 1 1 1 0 1 1
0 0 1 1 1 0 0
right
PC-1

6. 1 1 1 0 0 1 0
0 1 0 0 1 1 0
0 1 0 1 1 1 0
1 1 0 0 1 0 1
1 1 0 0 0 1 0
0 0 1 1 0 1 1
1 1 1 0 1 1 0
0 1 1 1 0 0 0
Left-right sau dịch
vòng trái lần 1

7. 1 1 1 0 0 1 0
0 1 0 0 1 1 0
0 1 0 1 1 1 0
1 1 0 0 1 0 1
1 1 0 0 0 1 0
0 0 1 1 0 1 1
1 1 1 0 1 1 0
0 1 1 1 0 0 0
0 0 0 0 1 0 1 1
0 1 0 0 1 1 1 0
1 0 1 0 0 1 1 1
1 1 0 0 1 0 1 0
1 1 0 1 1 0 1 0
1 1 0 1 0 0 1 0
1 2 3 4 5 6 7
8
15
22
29
36
43
50
Pc-2 : K1

8. 0 1 0 0 1 1
1 1 0 1 1 1
1 1 0 1 1 1
1 1 0 0 1 1
1 1 0 0 1 1
1 1 0 0 1 0
1 0 1 0 0 0
0 0 0 1 0 1
0 0 0 0 1 0
1 1 0 1 0 0
1 1 1 0 1 0
1 0 0 1 1 1
1 1 0 0 1 0
1 0 1 1 0 1
1 0 1 0 1 1
0 1 0 0 1 0
0 1 0 0 0 1
0 0 0 0 1 1
0 0 1 1 0 1
0 1 0 1 0 0
0 0 0 0 0 1
0 1 1 1 1 1
0 0 0 0 1 1
0 1 0 1 1 1
XOR =

9. 0 1 0 0 0 1
0 0 0 0 1 1
0 0 1 1 0 1
0 1 0 1 0 0
0 0 0 0 0 1
0 1 1 1 1 1
0 0 0 0 1 1
0 1 0 1 1 1
C1 = 1010
C2 = 1101
C3 = 0110
C4 = 1000
C5 = 0010
C6 = 1000
C7 = 0000
C8 = 1011