(d) Answer the following questions. (i) What is the additional information an adversary requires in order to crack the substitution ciphers? [10% (ii) Assume that Alice received a ciphertext message MMCTKLSZZ from Bob and the One- Time Pad (OTP) is '10 12 20 24 8 19 13 4 3'. What is Bob's plain text message? What is the OTP breaking time for this ciphertext message? You will need to reserve the produced equivalent values for the ciphertext message and the plain text in your answer, all in capital letters [15% In an OTP encryption system, the user A sends following two messages to the user B. He uses the Pad 1 for the message one and Pad 2 for the message two. What are the ciphertext messages? Explain what is the problem in OTP system and how can we solve it? Msg 1 1 0 1 1 1 0 0 0 1 1 0 1 Msg 21 0 0 0 0 1 0 0 10 0 0 Pad 11 0 0 0 0 1 Pad 2 1 0 1 1 1 0 1 1 1 0 0 0 0 0 0 0 0 1 [10 % (d) Answer the following questions. (i) What is the additional information an adversary requires in order to crack the substitution ciphers? [10% (ii) Assume that Alice received a ciphertext message MMCTKLSZZ from Bob and the One- Time Pad (OTP) is '10 12 20 24 8 19 13 4 3'. What is Bob's plain text message? What is the OTP breaking time for this ciphertext message? You will need to reserve the produced equivalent values for the ciphertext message and the plain text in your answer, all in capital letters [15% In an OTP encryption system, the user A sends following two messages to the user B. He uses the Pad 1 for the message one and Pad 2 for the message two. What are the ciphertext messages? Explain what is the problem in OTP system and how can we solve it? Msg 1 1 0 1 1 1 0 0 0 1 1 0 1 Msg 21 0 0 0 0 1 0 0 10 0 0 Pad 11 0 0 0 0 1 Pad 2 1 0 1 1 1 0 1 1 1 0 0 0 0 0 0 0 0 1 [10 %