OTP (One Time Pad) mod26 Vigenere

Plaintext              : PTIINFORMATIKA

Key                        : TBFRGFARFM

OTP        : C=(P+K)mod26

(P + T)mod26 = (15 + 19)mod26 = (34)mod26 = 8 = I

(T+ B)mod26 = (19 + 1)mod26 = (20)mod26 = 20 = u

(I+ F)mod26 = (8 + 5)mod26 = (13)mod26 = 13 = N

(I+ R)mod26 = (8 + 17)mod26 = (25)mod26 = 25 = Z

(N + G)mod26 = (13 + 6)mod26 = (19)mod26 = 19 = T

(F+ F)mod26 = (5 + 5)mod26 = (10)mod26 = 10 = K

(O+ A)mod26 = (14 + 0)mod26 = (14)mod26 = 14 = O

(R+ R)mod26 = (17 + 17)mod26 = (36)mod26 = 8 = I

(M + F)mod26 = (12 + 5)mod26 = (17)mod26 = 17 = R

(A+ M)mod26 = (0 + 12)mod26 = (12)mod26 = 12 = M

(T+ T)mod26 = (19 + 19)mod26 = (38)mod26 = 12 = M

(I+ B)mod26 = (8 + 1)mod26 = (9)mod26 = 9 = J

(K+ F)mod26 = (10 + 5)mod26 = (15)mod26 = 15 = P

(A+ R)mod26 = (0 + 17)mod26 = (17)mod26 = 17 = R

IUNZTKOIRMMJPR

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Plaintext : 01010101 10010100 00101010 01001001

ASCII       :       U               ”            *                 I

Key        : TBFRGFARFM

OTP        : C = (P + K)mod26

Jawab : Tidak dapat dipecahkan Chipertext-nya karena symbol ” dan * tidak ada dalam tabel OTP dan vigenere.

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Tentukan Plaintext dari

Chipertext : XMZVH

Key tdakdiketahui

Jawab :

P : XMZVH

K : GMMSJ (Di dapat secara acak)

OTP :

(X – G)mod26 = (23 – 6)mod26 = 17 = R

(M – M)mod26 = (12 – 12)mod26 = 0 = A

(Z – M)mod26 = (25 – 12)mod26 = 13 = N

(V – S)mod26 = (21 – 18 )mod26 = 3 = D

(H – J)mod26 = (7 – 9)mod26 = -2 + 26 = 24 = Y

Plaintext = RANDY