S (Secure Hash Algorithm) SHS (Secure Hash Standard) 1992 . S DS.
264 S 160- , D (Message Digest). DS, . , , .
, , S .
S , , , , , . , .
S. , 512 . : , , , 64 , 512, 64- .
32- :
= 067452301 = 0FD89 = 098DF D = 0x10325476 = 03D21F0. 512 512- , . , , , D, a, b, , d, :
= , b = , = , d = D, =20 . , b, , d, , .
S :
ft (, Y, Z) = (X Ù Y) Ú ((Ø X) Ù Z) t = 0...19, ft (, Y, Z) = Å Y Å Z t = 20...39, ft (, Y, Z) = (X Ù Y) Ú (X Ù Z) Ú (Y Ù Z) t = 40...59, ft (, Y, Z) = Å Y Å Z t = 60...79,t - .
:
t = 05827999 t = 0...19, t = 06D91 t = 20...39, t = 08F1D t = 40...59, t = 0621D6 t = 60...79.32- (0...15) 32- (W0...W79) :
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t - , Wt - t- , <<< S - S .
:
t 0 79 = ( <<< 5) + ft (b, c, d) + + Wt + t = d d = = (b <<< 30) b = = _.5.
.5. SHA
, b, , d, , , , D, , 512- . , , , D, .
SHA MD5 :
- S 160- -, " ", MD5, 128- -.
- SHA 80 , 64 MD5.
- , .