4.5.6.10 FoDR - Encryption

Question 1

What is meant by encryption

Answer 1

The process of scrambling data so that it cannot be understood if intercepted
in order to keep it secure during transmission

Question 2

What is meant by plain text

Answer 2

the message in a form that can be understood easily

Question 3

What is meant by cipher text

Answer 3

the encrypted message

Question 4

What is meant by a cipher

Answer 4

A cipher is a set of instructions (an algorithm) for encrypting plain text.

Question 5

Describe the process of Encryption

Answer 5

Plaintext is encrypted using a cipher. The cipher text is transmitted to the recipient. The ciphertext is decrypted using another cipher and an encryption key

Question 6

What are the 2 types of cipher

Answer 6

Caesar
Vernam

Question 7

What are the 2 types of Caesar Cipher, and explain how they work

Answer 7

Shift - shifts each letter of the plain text by an amount specified by the key. For example, if the key is 3, each letter is shifted three places to the right.
Random Substitution - each letter of the alphabet is replaced by another character randomly

Question 8

Why are Caesar ciphers easy to crack

Answer 8

• Certain letters are used normally more than others, meaning in the ciphertext there will be dominant repeated characters. By examining the ciphertext for frequently used characters it ill be easier to decrypt the message