The X3Dh Key Agreement Protocol

With E2EE, your message is encrypted at all times, as it finds its way through potential intermediaries. No one other than the intended recipient has the key to decrypt it. With a good E2EE protocol, neither intermediaries (mail application server, database) nor people with malicious intent would be able to read the messages you have sent. Without the need to execute a key convention protocol a second time between the same two users, a simple DH between alice and Bob`s identity keys should suffice, and perfect secrets before are not a problem, as the protocol would never be executed again. Only if the protocol has to be executed more than once would X3DH be needed to restore the secret of the perfect front. However, this vulnerability can be eliminated by a post-X3DH protocol (for example. B a protocol using the Double Ratchet algorithm).