- . , , - .
CBC CFB IV. - M. -, .
- , , - , - .
, - , .
, - . 4.5. :
h 0= IV,
hi = EA (B) Å C,
IV ( ); A, B C Mi, hi 1, (Mi Å hi 1), ( 0).
. 4.5. -. |
M Mi, , .
A, B , 64 . 52 , . 12 4.1.
4.1 ()
1. | |
2. | |
3. | |
4. | |
5. | |
6. | |
7. | |
8. | |
9. |
4.1 ()
10. | |
11. | |
12. |
. . 4.6.
. 4.6. . |
4.2.3. 34.1194
34.1194 - , . 2814789.
-, , 256 . 256 .
M 256 . c .
1. 256 .
2. 64- - H Ki (i = 1, 2, 3, 4) 2814789 .
|
|
3. .
:
- 256 ;
256 ;
2, 3 4 256 : 2 4 , 3
18 08 116 024 116 08 (08 18)2 18 08 (08 18)4 (18 08)4,
0 1.
, . : 256- 8- . 256- y = j (x), x 8- ; y 8- .
j (i + 1 + 4(k 1)) = 8× i + k,
i = 03, k = 18.
A (x) = (x 1 Å x 2) || x 4 || x 3 || x 2, xi 64 256- x, || .
:
i = 1, U = H, V = M.
W = U Å V, K 1 = (W)
K 2, K 3, K 4 :
U = A (U) Å i,
V = A (A (V)),
W = U Å V,
K i = (W).
64- K 1, K 2, K 3 K 4. 64- : H = h 4 || h 3 || h 2 || h 1. S = s 1 || s 2 || s 3 || s 4, s i = EKi (hi), i = 1, 2, 3, 4, EKi 2814789 .
. 256- η16 || η15 ||... || η1 16- .
Ψ :
Ψ (η16 || η15 ||... || η1) = η1 Å η2 Å η3 Å η4 Å η13 Å η16 || η16 ||... || η2.
- :
,
H -, M , Ψ i i - Ψ.
-.
:
;
, 256 ;
Σ, 256 ;
L, .
256 . i :
1.
2.
3. L , 256 2256. L.
: Σ Mi 256 . 2256. .
|
|
, .. ' :
1. ' , 256 .
2. .
3. L , 2256.
4. = c (', ).
5. = c(L, ).
6. = c(Σ, ).
- .