𝐂𝐨𝐝𝐞𝐬 𝐚𝐧𝐝 𝐂𝐢𝐩𝐡𝐞𝐫𝐬

𝐎𝐧𝐞 𝐓𝐢𝐦𝐞 𝐏𝐚𝐝 𝐂𝐢𝐩𝐡𝐞𝐫

One Time Pad Cipher A.K.A. Vernam Cipher or Perfect Cipher

This cipher is one of the hardest ciphers to be decoded. The cipher diagram is here:

A-0
B-1
C-2
D-3
E-4
F-5
G-6
H-7
I-8
J-9
K-10
L-11
M-12
N-13
O-14
P-15
Q-16
R-17
S-18
T-19
U-20
V-21
W-22
X-23
Y-24
Z-25

Now.. for example the equivalent number of the given "plaintext" will be searched then add the equivalent numbers of the "keyword". Take note that when the "keyword" exceeds the number of letters or numbers of the "plaintext", the extra letters will be taken out/ removed. The sum of the plaintext and keyword will be translated to letters, then that will be the "CIPHERTEXT".
When the sum reaches 26 and there are still more left, the counting will be reset at 1. Example: 24, 25, 26, 1, 2,.... that will be the counting until the remaining numbers are distributed. When the sum is exact 26, that is counted as 0 so it was letter A

(Encrypting):

Plaintext: JULS Keyword: BABAS

J - 9 + 1 -B = 10
U - 20 + 0 -A = 20
L - 11 + 1 -B = 12
S - 18 + 0 -A = 18
×- S 
10 = K
20 = U
12 = M
18 = S

CIPHERTEXT: KUMS

Now.. on the decrypting process, the ciphertext will be translated into numbers, then it will be subtracted to the translated keyword.

(Decrypting)

Ciphertext: KUMS Keyword: BABAS

K = 10 - 1 = B = 9
U = 20 - 0 = A = 20
M = 12 - 1 = B = 11
S = 18 - 0 = A = 18

9 = J
20= U
11= L
18= S

~~~CTTRO