ShiftCipher

A simple shift cipher, also known as a Caesar cipher

Installation

Add this line to your application's Gemfile:

gem 'shift_cipher'

And then execute:

$ bundle

Or install it yourself as:

$ gem install shift_cipher

Usage

Initialise the Caesar cipher

  cipher = ShiftCipher::Caesar.new(3) # initialised with an offset of 3 ('a' = 'd')

or

  cipher = ShiftCipher::Caesar.new(-3) # initialised with a negative offset of 3 ('a' = 'x')

or

  cipher = ShiftCipher::Caesar.new('d') # initialised with an offset of 3 ('a' = 'd')

Encrypt a message:

  encrypted_message = cipher.encrypt('hello world') 
  p encrypted_message # => "khoorzruog"

Decrypt a message:

  decrypted_message = cipher.decrypt('khoorzruog') 
  p decrypted_message # => "helloworld"

Development

After checking out the repo, run bin/setup to install dependencies. Then, run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release to create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

1. Fork it ( https://github.com/[my-github-username]/shift_cipher/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request