class ActiveSupport::MessageEncryptor

def _encrypt(value)
  cipher = new_cipher
  cipher.encrypt
  cipher.key = @secret
  # Rely on OpenSSL for the initialization vector
  iv = cipher.random_iv
  encrypted_data = cipher.update(@serializer.dump(value))
  encrypted_data << cipher.final
  [encrypted_data, iv].map {|v| ::Base64.strict_encode64(v)}.join("--")
end