The Caesar cipher but better !
The Vigenère cipher is a more efficient version of the Caesar cipher. It can be easily tweaked to make it almost unbreakable !
You can decipher the message with a tabula recta if you have the key.
Compile with cc -Wall -Werror -Wextra main/main.c functions/*.c
Syntax to use the code : ./executable_name "key" "plaintext"
Tip
You can use sentences with non-alphabeticals !