DS (Digital Signature Algorithm) 1991 . DSS (Digital Signature Standard). DS ..
: G - , L (512 £ L £ 1024); q - 160 ( (-1)). G, , q .
X, 1 < < q. .
Y = GX mod .
Y .
h(). DSS S (Secure Hash Algorithm).
, - m:
m = h(), 1<m<q,, 1< < q, r:
r = (GK mod ) mod q.s:
s = ((m + r * X)/K) mod q.(r,s)
S = (r,s).
, (,r,s).
(,r,s)
0 < r < q, 0 < s < q, .
w = (1/s) mod q,-
m = h()u1 = (m * w) mod q, u2 = (r * w) mod q.
Y
v = ((Gu1 * Yu2) mod ) mod qv = r.
v = r , S=(r,s) .
, , , S=(r,s) X, Y. , , ( X) .
DS :
1. , .. G ( 512 1024 ), q, X, r, s 160 , 320 .
2. , r, s, q 160 , .
3. u1, u2, v, w q 160 , .
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DS , q:
s = ((m + rX)/K) (mod q), w = (1/s) (mod q),.
, DS . , r - m. r. -1 . , , s r -1. DS.