Kamis, 08 Desember 2011

Algoritma RSA


Misalkan
p = 3
q = 7
n = p.q
   = 3 x 7
   = 21
m = (p-1) (q-1)
     = (3 -1)(7 – 1)
     = 12
e * d mod 12 = 1
e = 5
d = 17
public key = (e,n) = (5,21)
private key = (d,n) = (17,21)

T          O         M         I
84        79        77        73
Proses Enkripsi dan Deskripsi
T = 84
Enkripsi
Deskripsi
C = M ^ e mod n
M = C ^  d mod n
8 ^ 5 mod 21 = 8
8 ^ 17 mod 21 = 8
4 ^ 5 mod 21 = 16
16 ^ 17 mod 21 = 4
                                   
O = 79
Enkripsi
Deskripsi
C = M ^ e mod n
M = C ^  d mod n
7 ^ 5 mod 21 = 7
7 ^ 17 mod 21 = 7
9 ^ 5 mod 21 = 18
18 ^ 17 mod 21 = 9
                                   
M = 77
Enkripsi
Deskripsi
C = M ^ e mod n
M = C ^  d mod n
7 ^ 5 mod 21 = 7
7 ^ 17 mod 21 = 7
7 ^ 5 mod 21 = 7
7 ^ 5 mod 21 = 7

I = 73
Enkripsi
Deskripsi
C = M ^ e mod n
M = C ^  d mod n
7 ^ 5 mod 21 = 7
7 ^ 17 mod 21 = 7
3 ^ 5 mod 21 = 12
12 ^ 17 mod 21 = 3