def build(data, salt)
        if builder.is_a?(Proc)
          builder.call(data, salt)
        else
          builder.send(:build, data, salt)
        end
      end
def build(data, salt)
        if builder.is_a?(Proc)
          builder.call(data, salt)
        else
          builder.send(:build, data, salt)
        end
      end
Builds the value to hash based on the data being encrypted and the salt
 being used to seed the encryption algorithm