6. Encryption

Question 1

Plaintext

Answer 1

In human, legible form

Question 2

Ciphertext

Answer 2

Data which has been encrypted

Question 3

Key

Answer 3

Data that is used to encrypt and decrypt other data

Question 4

Caesar Cipher

Answer 4

A substitution cipher which shifts the whole alphabet by +-25 and assigns the alphabet letters to be the same as the same letter of which is in the equivalent position in the new alphabet

*Can be broken by frequency analysis

Question 5

Vernam Cipher

Answer 5

• Only method proven to that is most effective
• Key must be equal or longer than the Plaintext
• Sender and Recipient must share secretly
• Key must be random and one use only

Question 6

Uernam Cipher Method

Answer 6

1. Convert each plain text into numerical value
2. Convert one time key into numerical
   value
3. Xor the numbers together and convert back into characters