Vigenère Cipher

Contents

1. Description
2. Installation
3. Usage

Description

A C-based Implementation of the Vigenère Cipher.

Installation

• Compile and Execute on GNU/Linux using GCC

$ gcc vigenere.c -o vigenere
$ chmod +x vigenere
$ ./vigenere

• Compile and Execute on Windows NT using the VS Developer Command Prompt

$ cl vigenere.c
$ .\vigenere.exe

Usage

./vigenere -h

usage: ./vigenere [-h] "message" [-m MODE] [-k "KEY"]

positional arguments:
      message  specifies the message to encrypt/decrypt (A-Z, a-z).
      -m       encrypt/decrypt the subsequent message.
               (0 = encrypt, 1 = decrypt, 0 = default)
      -k       specifies the keyword to use (variable length, ASCII-only).

optional arguments:
      -h       displays help message and usage information.