DS (Digital Signature Algorithm) 1991. DSS (Digital Signature Standard). DS - ..
: G - , L (512 ≤ L ≤ 1024); q - 160 ( (-1)). G, , q .
X, 1 < < q. .
= G 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.
v = ((Gu1 * Yu2) mod ) mod q
v = 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 , .
DS , q:
s = ((m + rX)/K) (mod q), w = (1/s) (mod q),
.
, DS . , r - m. r. -1 . , , s r -1. DS.