Present::Cipher

A Ruby implementation of the PRESENT block cipher.

Installation

Install the gem and add to the application's Gemfile by executing:

$ bundle add present-cipher

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install present-cipher

Usage

Present::Cipher encrypts 64-bit plaintexts and decrypts 64-bit ciphertexts using 80- or 128-bit keys.

Generating a Key

Using SecureRandom:

require "present/cipher"
require "securerandom"

key = SecureRandom.bytes(Present::Cipher::KEY_BYTESIZE_80) # Make sure to save this value somewhere safe!

If you prefer, pass Present::Cipher::KEY_BYTESIZE_128 to generate a 128-bit key.

Encrypting

require "present/cipher"

cipher = Present::Cipher.new(key)
ciphertext = cipher.encrypt(plaintext)

Decrypting

require "present/cipher"

cipher = Present::Cipher.new(key)
plaintext = cipher.decrypt(ciphertext)

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also 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.

Contributing

Bug reports and pull requests are welcome on Codeberg at https://codeberg.org/htp/present-cipher. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Present::Cipher project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.