(k-Rail Fence Cipher): The rail fence cipher is a transposition cipher, where a plaintext message is enciphered into a ciphertext message by performing some sort of permutation on the plaintext letters. Using this encryption technique, a plaintext is written down as a sequence of diagonals and then reads off as a sequence of rows. For example, to encipher the message HELLO CSEN 4340 STUDENTS! with a rail fence of depth 2, we write the following: H L O S N 3 0 T D N S E L C E 4 4 S U E T ! The resulting ciphertext is: HLOSN30TDNSELCE44SUET! The decryption function is performed as follows: - Compute the length of ciphertext. Let m be this length. - Let k be the number of rails (i.e., key). Reserve m placeholders on the k-rail fence in the same way a plaintext was placed on a k-rail fence. - Assign the ciphertext letters to those placeholders row by row, starting from the top one. - Read off the resulting plaintext as a sequence of diagonals. 1. Write an algorithm for a k-rail fence cipher, where k 2. 2. Show that your proposed algorithm is correct using an informal proof (i.e., discussion). 3. Give a program corresponding to your proposed algorithm, using your favorite programming language. Your program should simulate this cipher and display the ciphertext along with the corresponding plaintext and key. The implementation of this k-rail fence cipher software should be as structured as possible. You should have a user-friendly interface showing all the steps of this cipher, including encryption and decryption.

(k-Rail Fence Cipher): The rail fence cipher is a transposition cipher, where a plaintext message is enciphered into a ciphertext message by performing some sort of permutation on the plaintext letters. Using this encryption technique, a plaintext is written down as a sequence of diagonals and then reads off as a sequence of rows. For example, to encipher the message HELLO CSEN 4340 STUDENTS! with a rail fence of depth 2, we write the following: H L O S N 3 0 T D N S E L C E 4 4 S U E T ! The resulting ciphertext is: HLOSN30TDNSELCE44SUET! The decryption function is performed as follows: - Compute the length of ciphertext. Let m be this length. - Let k be the number of rails (i.e., key). Reserve m placeholders on the k-rail fence in the same way a plaintext was placed on a k-rail fence. - Assign the ciphertext letters to those placeholders row by row, starting from the top one. - Read off the resulting plaintext as a sequence of diagonals. 1. Write an algorithm for a k-rail fence cipher, where k 2. 2. Show that your proposed algorithm is correct using an informal proof (i.e., discussion). 3. Give a program corresponding to your proposed algorithm, using your c++ programming language. Your program should simulate this cipher and display the ciphertext along with the corresponding plaintext and key. The implementation of this k-rail fence cipher software should be as structured as possible. You should have a user-friendly interface showing all the steps of this cipher, including encryption and decryption.