Question

frame additive cipher table (key=4)​

Answer 1

Answer:

Step-by-step explanation:

Hc documents Jesus been

Answer 2

additive cipher table (key=4)​ is given by adding the key and taking the remainder.

• encryption C = ( P +  Key ) mod 26
• decryption D = ( C - key ) mod 26
• Mod 26 is used to make sure the value lies between 0 to 25.

The idea is that each alphabets are represented in numeric form.

• ie., A = 0
• B = 1
• C = 2 ....
• Z = 25

Now take the word Hello.

Here,

• H = 7
• E = 4
• L = 11
• O = 14

Applying Encryption :

• C ( H ) = P + K mod 26  = 7 + 4  mod 26 = 11 = L
• C ( E ) = P + K mod26 = 4 + 4 mod 26 = 8 = I
• C ( L ) = 11 + 4 mod26 = 15 = P
• C ( O ) = 14 + 4 mod 26 = 18 = S

Encrypted word is : LIPPS

We can apply the decryption to get back the original word, only if we know the key.