/ / /
:
AES 128bit) 196bit 256bit 128bit) 10 12 14 196bit) 12 12 14 256bit) 14 14 14
(n, e) (n, d) M M : 2 ( 101 5) [e ] [e ] n = p * q (p q ) (n) = (p-1)(q-1) gcd( (n), e) = 1; 1 < e < (n) d = e^-1 (mod (n)) M e (mod n) [d ] [d ] C C : M = C d (mod n) = (M^e ^d (mod n) = M^ed (mod n) = M (mod n)
( ) A A B B OK
MD
1 MD?? 4. 2 1. 2. 3. MD 1.? 2. 3.??? 4.
(1) challenge( (2) (3) response (4)
N Pass Phrase k Pass Phrase N+1 Pass Phrase k-1 Pass Phrase
3 2 1