Consider a Caesar cipher and assume that the plaintext message is in English. Decrypt the following ciphertext by giving a brief explanation: KNXMNSLKWJXMBFY JWGJSIXFIRNY XB TWIKNXMWFSITAJWMJORNSLESDIFD Note: Use the following frequency distribution of the letters in the English language for the cryptanalysis: of 3,68 n @ P 4 7,10 7,144 2.200,20 H 8,05 b 1,092 e Table 1: e h 12,31 2,28 1,61 5,14 F a 1 U 6,036,50 9,50 3,1 T 7,18 0,1 U w A 0,42 4.03 V 0,01 2,03 0,2 1,58 0,00 z 1 m (a) [10 points] Caesar cipher is an example of classical cryptosystem. What can be the main drawback of the substitution cipher given above? (b) [10 points] Steganography is the art and science of hiding information by embedding messages within other, seemingly harmless messages. Take the third letter in each word of the encrypted message above and find the emerging message. (c) [10 points] We consider a ciphertext-only attack on a substitution cipher and assume that the plaintext message is in English. Decrypt the following ciphertext by giving a brief explanation: XTHQTXISTRFY Y JWMTBKFW What can be the main drawback of the substitution cipher given above?