Vigenere Cipher is a method of encrypting alphabetic text. It uses a simple form of polyalphabetic substitution. A polyalphabetic cipher is any cipher based on substitution, using multiple substitution alphabets. The encryption of the original text is done using the Vigenère square or Vigenère table. https://www.geeksforgeeks.org/vigenere-cipher/
make
or
g++ crypt.cpp -o crypt.out
./crypt.out