DSA (Digital Signature Algorithm) 1991 . DSS (Digital Signature Standard). DSA .
: G , L (512 < L < 1024); q 160 ( ( 1)). G, P, q .
X, 1< < q. X .
. Y . Y .
h(). DSS SHA.
, - m = h (M), 1 < m < q, K, 1< K < q, r = (GK (mod P))(mod q). X . r s S = (r, s) .
, (, r, s).
(, r, s) 0 < r < q, 0 < s < q , .
,
- m = h (M) u 1 = m × w (mod q), u 2 = m × r (mod q).
Y
v = r.
v = r , S = (r, s) .
DSA :
1. , .. G ( 512 1024 ), q, X, r, s 160 , 320 .
2. K, r, s, X q 160 , .
3. u 1, u 2, v, w q 160 , .
DSA , q:
, ,
.
, DSA . , r - m. K r. K 1 K. , , s r K 1. DSA.
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|
4.3.4.
34.1094 34.102001
, 34.1094, DSA. : 509 512 1020 1024 ; q ( 1), 254...256 ; , ( 1), ,
aq (mod p) = 1; , q; = (mod p).
, - h (), 34.1194.
, q . , .
M, , .
1. k, k < q.
2. m = h (M), r = (ak (mod p))(mod q)
s = (x × r + k × m)(mod q). m (mod q) = 0, m . r = 0, k . : r mod 2256 s mod 2256. .
3. , :
v = h (M) q 2 (mod q),
z 1 = s × v (mod q),
z 2 = ((q r) × v) (mod q),
.
u = r, .
2002 . 34.102001. . .
.
1. p , p > 2255.
2. Ep (a, b), J a b.
:
, ,
, , .
3. m,
.
4. q, :
m = n × q, n ³ 1;
2254 < q < 2256.
5. P ¹ O Ep (a, b), (xP, yP), q × P = O.
6. - h, 34.1194.
: ( d, 0 < d < q) ( Q (xQ, yQ), Q = d × P).
:
pt ¹ 1(mod q), t = 1, 2,... B, B B ³ 31;
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m ¹ p;
1728.
d M, S. .
1. - : hM = h (M).
2. a, hM, e º a (mod q). e = 0, e = 1.
3. C () k, 0 < k < q.
4. C = k × P r º xC (mod q), xC x- C. r = 0, .
5. s º (r × d + k × e)(mod q). s = 0, k 4 5.
6. , r s, .
M, S Q, . .
1. S, r s. 0 < r < q 0< s < q, . .
2. - M: hM = h (M).
3. a, hM, e º a (mod q). e = 0, e = 1.
4. v º e 1 (mod q).
5. z 1 º s × v (mod q) z 2 º r × v (mod q).
6. C = z 1× P + z 2× Q R º xC (mod q), xC x- C.
7. R = r, , , .
1. RSA.
2. .
3. -.
4. .
5. SHA.
6. 34.1194.
7. RSA.
8. (EGSA).
9. DSA.
10. 34.1094.
11. 34.102001.
: RSA, , -. . SHA (Secure Hash Algorithm), - , 34.1194. RSA, , DSA (Digital Signature Algorithm), 34.1094 34.102001.