def box(message)
      nonce = generate_nonce
      cipher_text = @box.box(nonce, message)
      nonce + cipher_text
    end
def box(message)
      nonce = generate_nonce
      cipher_text = @box.box(nonce, message)
      nonce + cipher_text
    end
Encrypts the message with a random nonce

 Encrypts the message with a random nonce, then returns the ciphertext with
 the nonce prepended.  Optionally encodes the message using an encoder.

 @param message [String] The message to encrypt

 @return [String] The enciphered message