SSL

Secure Socket Layer (SSL) is a protocol developed by Netscape in 1996 which quickly became the method of choice for securing data transmissions across the Internet. SSL is an integral part of most web browsers and web servers and makes use of the public-and-private key encryption system developed by RSA.  

In order to make an SSL connection, the SSL protocol requires that a server should have a digital certificate installed. A digital certificate is an electronic file that uniquely identifies individuals and servers. Digital certificates serve as a kind of digital passport or credential which authenticate the server prior to the SSL session being established.