To ensure a safe communication between servers, it is advised to use the transfer method Perfect Forward Secrecy. A safe connection is established, when the code of the communication is not transferred or stored anywhere – otherwise it could get intercepted or hacked. Instead, both communication partners agree on a key, specifically generated for one session, which will be deleted after the session. The most common method is the Diffie-Hellman key exchange. The communication partners jointly establish a shared key via messages, therefore, even if someone is wiretapping the messages, it is still impossible to guess the code. Since the key will never be stored permanently, neither of the communication partners is able to reveal the key.