N

1
???????? ??? ????????? ???? 28147-89

• N ??????? ???? (64 ????)?
• X ????????? ???? (32 ????)?
• H ??????? ?????

2
?????????? ????????? ???? ????????? ???? 28147-89
gost32 PROC iloop mov EBP,EAX
add EAX,ESI add
ESI,4 REPT 3 xlat
ror EAX,8 add
EBX,100h ENDM xlat sub
EBX,300h rol EAX,3
xor EAX,EDX mov EDX,EBP
loop iloop ret gost32 ENDP
3
??????? XLAT
EAX
??????
ESBX
EAX
AL
AL
AL
4
n
GF(? )

• ?????????????? ???? ? - ??????? ?????
• ????? ????????? ???? pn - ??????????? ???????
  ???????? ?????
• ? ???? ?????????? ???????? ???????? ? ?????????
• ? ???? ?????????? ???????? 0, 1, -a, a-1
• ? ???? ?????????? ?????? ??????? ?, ??????????
  ???????????

5
GF(7)

• ????????
• 4 5 9 mod 7 2
• ?????????
• 5 4 20 mod 7 6

6
???? ????? ?????????????? 2
7
n
???????? ? GF(2 )

• (x6 x4 x2 x 1) (x7 x 1)
• x7 x6 x4 x2 2x 2 x7 x6 x4
  x2

8
n
????????? ? GF(2 )

• f(?) x8 x4 x3 x 1
• (x6 x4 x2 x 1) (x7 x 1) mod (x8
  x4 x3 x 1)
• (x13 x11 x9 x8 x6 x5 x4 x3 1)
  mod (x8 x4 x3 x 1)
• x7 x6 1

9
??????????? ???????
f(?) x4 x 1
10
????????? ?????????
x3 (x3 1) mod (x4 x 1) ?3 ?14 ?2
x2
11
???????? ?????? ? ???????? ???????? ?????? (LFSR)
12
?????? ?????????? ?????
?(?) x8 x7 x5 x3 1
13
??????????? ?????????? ?????????? ?????
Lfsr PROC shl AX, 1 jnc Exit xor AX
, FeedBack Exit ret Lfsr ENDP
FeedBack ?????? ???????? ??????, ????????, ???
?(?) x8 x7 x5 x3 1 FeedBack 0D4h
14
?????????????? ????? ? ?????????????? R-?????
AL ??????? ???? AH ???????? ??????????????
DS BX ????? ??????? AddrH
AddrH
DS BX
Hsize 256 Rbox8 PROC push BX xlat add
AL, AH add BX, HSize xlat pop
BX ret Rbox8 ENDP
DS BXHSize
15
??????

• ???????? ? ?????? ?????????????? ????? ???
  ????????? ?????, ?? ? ?? ?? ????? ???????
  ??????????? ??? ??? ??????????
• ?????????? ??????????? ???????, ???? ???????
  n ?????? ?????? ?????????? ????????? ????
  GF(2n)?
• ?????????? ??????????? ???????, ???????????
  ???????? 4- ? 8-????????? ??????
• ?????????? ??????????? ???????, ???????????
  ???? ?????? ??????????????? ?????????