In cryptography, a substitution cipher is a method of encoding by which units of plaintext are replaced with cipher text, 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. If the file does not exist, the program should terminate with a file not found error message displayed on the screen. The output (encrypted text) will be displayed on the screen as 50 character per line. or this program, the following keys are used Plaintext alphabet: ABCDEFGHIJKLMNOPQRSTUVWXYZ Cipher text alphabet: EMNVDLWAUCPOKXQBIZJRYTGSHF Numbers 0123456789 Cipher numbers 9876543210 Special symbols Cipher special symbols : ! $%& '()*+,-./;?@{ {}] [@?>=<: space replacer symbols>