Enable multiparameter attribute form submission for encrypted fields in Ruby on Rails http://stackoverflow.com/questions/17482507/correct-way-to-handle-multiparameter-attributes-corresponding-to-virtual-attribu Simply drop this into config/initializers and use attr_encrypted_default instead of attr_encrypted. I'm working on an update to attr_enc…

encrypted_attribute_helper.rb

if defined?(ActiveRecord::Base)
  class ActiveRecord::Base
    protected

    class EncryptedAttributeClassWrapper
      attr_reader :klass
      def initialize(klass); @klass = klass; end
    end

    def self.encrypted_attribute_class_wrappers
      @encrypted_attribute_class_wrappers ||= {}
    end

    # Consider using alias_method_chain to replace
    # the built-in method.
    def self.attr_encrypted_default(*args)
      options = args.last.is_a?(Hash) ? args.pop : {}
      
      # Not required functionality, but I'd like to make
      # attr_encrypted do this natively too.
      options = {
        :key => ENV['DEFAULT_FIELD_ENCRYPTION_KEY'],
        :marshal => true
      }.merge(options)

      if klass = options.delete(:class)
        attribute_sym = args.first.to_sym
        self.encrypted_attribute_class_wrappers[attribute_sym] =
          EncryptedAttributeClassWrapper.new(klass)
      end

      new_args = args + [options]
      attr_encrypted *new_args
    end

    # http://stackoverflow.com/questions/17482507/correct-way-to-handle-multiparameter-attributes-corresponding-to-virtual-attribu
    alias_method :column_for_attribute_base, :column_for_attribute
    def column_for_attribute(attribute)
      attribute_sym = attribute.to_sym
      if encrypted = self.class.encrypted_attributes[attribute_sym]
        column_info = self.class.encrypted_attribute_class_wrappers[attribute_sym]
        column_info ||= column_for_attribute_base(encrypted[:attribute])
        column_info
      else
        column_for_attribute_base(attribute)
      end
    end
  end
end