The Enigma Cipher is an encryption algorithm that was used during the early stages of World War II, and cracked by Polish mathematicians led by Marian Rejewski. Based on their analysis of the Enigma Cipher, they developed a machine called the Bomba to help them decrypt intecepted messages. However, changes to the cipher in the late 1940s rendered it useless. Once these changes took place, Alan Turing and others worked to create a similar machine called the Bombe which helped the Allies win the war.
You can learn more about Enigma machine at the link here.

• the program is run via the command line and accepts text for encryption and decryption that is provided within a text file (see instructions below)
• decryption is done automatically using the previous encryption key if a key and date argument are not provided
• special characters are accepted but are not encrypted using the cipher
• the cipher accepts upper and lowercase letters, however all text is output in lowercase

Download or clone this repo
(ex. git clone paste_name_of_repo_here)

Navigate to the repo folder on your computer

Add any text you would like to encrypt to the file message.txt

From your terminal, run the following command:

`ruby ./lib/encrypt.rb message.txt encrypted.txt`  

If you'd like to choose your own encryption key, simply choose a 5-digit number and provide it at the end of the command, like so:

`ruby ./lib/encrypt.rb message.txt encrypted.txt 12345` 

You can also add an optional 6-digit date argument for the encryption method like so:

`ruby ./lib/encrypt.rb message.txt encrypted.txt 12345 123122`  

Your encrypted message can be found inside of the text folder at the file path below:

`enigma/text/encrypted.txt`  

To decrypt the message, type the command below into your terminal:

`ruby ./lib/decrypt.rb encrypted.txt decrypted.txt`  

If you want to use a specific decryption key and date, type them at the end of the command above (the format should be similar to the encryption command with key and date arguments)

The encrypted or decrypted message can be found in the corresponding text file inside of the text folder

In additon to your encrypted or decrypted message, your key and date values are returned both in your terminal, as well as in corresponding text files inside of the text file folder

Encrypt and Decrypt methods are complete, and the encrypt/decrypt Command Line Interfaces are successfully implemented.

A cryptable module was implemented to house the encrypt and decrypt behavior. Inheritence was not used as it didn't make sense based on the interaction pattern for this program. Specific encrypt and decrypt methods were left in the Enigma class to follow the interaction pattern provided, as well as to help the logic flow. Code is DRY and follows SRP.

Code is neat, properly indented, and variable names make sense and are easy to understand. 100% of methods are under 7 lines of code. Enumerables used are best choice for each application.

Tests follow interaction pattern and most tests were written before methods, and all methods were written and refined using pry. Stubs were used to help test methods that use randomness. Test coverage metrics are at 100%.

over 60 commits with standardized naming conventions

13 pull requests with descriptions regarding updates or checkpoints reached with each merge