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Part 1:(Encryption and Decryption) The function E(x)=(ax+b) MOD 26 defines a valid Affine cipher of a letter ' x '. the coefficients ' a ' and ' b ' are integers between 0 and 25 , and ' a ' has to be relatively prime to 26 . Recall that the numerical equivalents of the English letters are as follows: 1) Encrypt the plaintext 'NETWORK SBCURITY' with the Affine cipher E(x)=(7x+2)mod26.(1pt) 2) Find E(y)=(cy+d) MOD 26, the inverse function of E(x), or the decryption function. (1 pt) 3) Decrypt the following ciphertext using E'(y): "QWIDMFER YQGEPQB". (1 pt) art 2:(Cryptanalysis) (2 pts) Ciphertext: CIIHTEBNRENBRRDFMANRADGERYTSTFIOEISUFEMOBAIYDNRSUTSRAOBGFLGCEBORFRX TNAB. Decrypt the above ciphertext which was obtained from English text using a columnar transposition. As a strategy, use brute force cryptanalysis to find the correct key (column order)