Due Date: 10 29 2018 Sections 3 and 4 In cryptography, a substitution cipher is a method of encoding by which units of plaintext are replaced with ciphertext, according to a regular system; the "units" may be single letters (the most common), pairs of letters, triplets of letters, mixtures of the above, and so forth. There are a number of different types of substitution cipher. One type of substitution cipher is simple substitution cipher which operates on single letters. Substitution of single letters separately-simple substitution-can be demonstrated by writing out the alphabet in some order to represent the substitution. This is termed a substitution alphabet Keys for the simple substitution cipher usually consist of 26 letters. Write a C++ program to encrypt or cipher a text file ( eFile.txt ). The text files does contain small letters, capital letter, numbers, spaces, and symbols. The output (encrypted text ) will be displayed on the screen as 50 chareatcer per line