EncryptableAttributes 
With the encryptable_attributes gem, you transparently encrypt and decrypt attributes of an ActiveRecord model. It uses ActiveSupport::MessageEncryptor to encrypt and decrypt values and provides a simple class-level DSL for configuration.
Installation
Add this line to your application's Gemfile:
gem 'encryptable_attributes'
And then execute:
$ bundle
Or install it yourself as:
$ gem install encryptable_attributes
Usage
Consider a simple ActiveRecord model Message with a title and a body field. To store those attributes' values encrypted, use the following code snippet.
class Message < ActiveRecord::Base
include EncryptableAttributes::Base
secure_key ENV.fetch('SECRET_KEY')
secure_attrs :title, :body
end
ActiveRecord models use an attributes hash internally to keep attributes. EncryptablesAttributes overrides the accessor methods for the corresponding attributes and encrypts given values before storing them in the attributes hash and decrypts them when reading them from the attributes hash.
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. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/nsommer/encryptable_attributes.
License
The gem is available as open source under the terms of the MIT License.