##########################################################################
Jika diketahui :
p
= 3
q
= 7
Penyelesaian : 
n
= p.q
  
= 3 x 7
  
= 21
m
= (p-1) (q-1)
    
= (3 -1)(7 – 1)
    
= 12
e
* d mod 12 = 1 (Cari bilangan prima yang jika mod M hasilnya 1)
e
= 5
d
= 17 
public
key = (e,n) = (5,21)
private
key = (d,n) = (17,21)
S         
I           S        
 J          A         R
83       
73        83       
74       65         82
##########################################################################
Proses
Enkripsi dan Deskripsi
S
= 83
| 
Enkripsi | 
Deskripsi | 
| 
C
  = M ^ e mod n | 
M
  = C ^  d mod n | 
| 
8
  ^ 5 mod 21 = 8 | 
8
  ^ 17 mod 21 = 8 | 
| 
3
  ^ 5 mod 21 = 12 | 
12
  ^ 17 mod 21 = 3 | 
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 | 
S
= 83
| 
Enkripsi | 
Deskripsi | 
| 
C
  = M ^ e mod n | 
M
  = C ^  d mod n | 
| 
8
  ^ 5 mod 21 = 8 | 
8
  ^ 17 mod 21 = 8 | 
| 
3
  ^ 5 mod 21 = 12 | 
12
  ^ 17 mod 21 = 3 | 
J
= 74
| 
Enkripsi | 
Deskripsi | 
| 
C
  = M ^ e mod n | 
M
  = C ^  d mod n | 
| 
7
  ^ 5 mod 21 = 7 | 
7
  ^ 17 mod 21 = 7 | 
| 
4
  ^ 5 mod 21 = 16 | 
16
  ^ 17 mod 21 = 4 | 
A
= 64
| 
Enkripsi | 
Deskripsi | 
| 
C
  = M ^ e mod n | 
M
  = C ^  d mod n | 
| 
6
  ^ 5 mod 21 = 6 | 
6
  ^ 17 mod 21 = 6 | 
| 
4
  ^ 5 mod 21 = 16 | 
16
  ^ 17 mod 21 = 4 | 
R
= 82
| 
Enkripsi | 
Deskripsi | 
| 
C
  = M ^ e mod n | 
M
  = C ^  d mod n | 
| 
8
  ^ 5 mod 21 = 8 | 
8
  ^ 17 mod 21 = 8 | 
| 
2
  ^ 5 mod 21 = 11 | 
11
  ^ 17 mod 21 = 2 | 
