. ( ) , : . , , .
, , . , , , , , .
K , :
1 () = ,
D2 () = .
, . , . , .
, . N , , : K1 j K2 j, j . , , , , . 3 9, K1 9 9- , K2 9. , 9, , , 3- .
9 3, 3- K1 3 3. , , 9 K2 3. 1, 2, 4, 8, 10 N .
( N 2* N ), , . , m - K2 m: , m, .
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. :
1. ( RSA);
2. ( -);
3. ( -).
RSA.
RSA. (R. Rivest), (A.Shamir) (L. Adleman) 1978 .
, 1 . , , .
. , p, P =2・3・5・7・・ p.
P +1. p , P. , .
:
2・3+1=7; 2・3・5+1=31; 2・3・5・7+1=211;
2・3・5・7・11+1=2311; 2・3・5・7・11・13+1=30031=59・509.
, , 1.
, i mod j i j. RSA, , .
1. q.
2. n q (n=p·q).
3. , d. ( 1) · (q 1).
4. , (·d) mod ((p 1) · (q 1)) = 1.
5. n, d n.
, { , n }, :
, M(i);
, M(i) (i) = (M(i)e) mod n. , {d, n}, : M(i)=(C(i)d) mod n. M(i), .
RSA , , n p q, x x(p-1)(q-1) mod n = 1.
RSA- . (- y):
(x(-y)(p-1)(q-1)) mod n = 1(-y) = 1.
x:
(x(-y)(p-1)(q-1)+1) mod n = 1 · x = x.
, . d ,
e·d+(p-1)(q-1) ·y = 1, e·d = (-y)(p-1)(q-1)+1.
, (e·d). (xe·d) mod n = x.
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ci = ((mi)e)mod n d m:
((ci)d)mod n = ((mi)e·d) mod n = mi.
RSA CAB. ( ).
1. = 3 q= 11.
2. n= 3 · 11=33.
3. (1) (q1)= 20. d , 20, d= 3.
4. . , (· 3 ) mod 20 = 1, 7.
5. 0...32. 1, 2, 3. 312. , {7, 33}:
(1)=(7) mod 33 = 2187 mod 33 = 9,
(2) = (17) mod 33 = 1 mod 33 = 1,
() = (27) mod 33 = 128 mod 33 = 29.
6. {9, 1, 29}, , {3, 33}:
M(1) = (93) mod 33 = 729 mod 33 = 3,
(2) = (13) mod 33 = 1 mod 33 = 1,
() = (293) mod 33 = 24389 mod 33 = 2.
, CAB.
RSA , , . () . , 200 ( ), ( 1023).
RSA . , . Microsoft, Apple, Sun Novell.
RSA , Ethernet, -, Zaxus (Rasal). , Internet, S/MIME, SSL S/WAN, , , , , .
RSA BSAFE 500 . RSA, , Internet.