Q1.

For each plaintext and ciphertext find out which method of encryption was used and write down the key that was used for this method

Plaintext: GOOD

Ciphertext: OVUA

The method of encryption is :

-Shift Cipher

-Substitution Cipher

-Vigenere Cipher

-none

Q2.

An attacker collects the following Cipher, encoded using shift Cipher method, and he/she performs Brute-Force cryptanalysis on the cipher to reveal the key.

The collected cipher-text: UVACLYFZLJBYL

What is the used key?

what is the corresponding plaintext?