An apparatus and a method for an authentication protocol. A client generates a server unique identifier of a server prior to communicating with the server. An encrypted password generator module of the client calculates an encrypted password based on the server unique identifier, a username, and an unencrypted password. A communication request generator module of the client generates and sends a communication request to the server. The communication request includes a username, a client random string, a client timestamp, and a client MAC value. The client MAC value is computed over the username, the client random string, and the client timestamp, using the encrypted password as an encryption key.