SSL (Secure Sockets Layer) has been developed for transmitting private documents through Internet. It works by using a private key for encrypting data that is transferred over the SSL connection. By convention, URLs that require an SSL connection start with https:
The SSL protocol is designed to provide privacy between two communicating applications (a client and a server) and authenticate the server, and optionally the client. SSL requires a reliable transport protocol (e.g., TCP) for data transmission and reception.
The advantage of the SSL protocol is that it is application protocol independent. A higher level application protocol (e.g., HTTP, FTP, TELNET, etc.) can layer on top of the SSL protocol transparently.
The SSL Protocol can negotiate an encryption algorithm and session key as well as authenticate a server before the application protocol transmits or receives its first byte of data. All of the application protocol data is transmitted encrypted, thus ensuring privacy.