2. The ciphertext MBR OJFGA SWNTE CNK QJDIL NURW MBR XHMR was obtained by encrypting the plaintext THE QUICK BROWN FOX JUMPS OVER THE GATE using a Simple Substitution Cipher. (a) How much of the key is determined if this plaintext/ciphertext pair are known?

b) How many different possible keys could have been used to encrypt the plaintext?

(c) Decrypt the ciphertext MBR TRHLRP WHE HTHV CWND PNEYNE ZNN, which is known to have been encrypted with the same key. (d) What lesson can be learnt from conducting this exercise?