encrypt_attributes

https://github.com/aenain/encrypted_attributes

This gem provides a dead-simple encryption of string / text attributes of ActiveRecord and Mongoid models. Encryptor internally uses ActiveSupport::MessageEncryptor and therefore it uses 'aes-256-cbc' cipher by default. Gem does NOT require column with different name. From user perspective encryption is completely transparent - they use decrypted values all the time, but encrypted values are stored in database.