S-HTTP

S-HTTP is an extension to the HTTP protocol, to support sending data securely over the World Wide Web. Not all Web browsers and servers support S-HTTP.
Another technology for transmitting secure communications over the World Wide Web -- Secure Sockets Layer (SSL) -- is more prevalent. However, SSL and S-HTTP have very different designs and goals, so it is possible to use the two protocols together. Whereas SSL is designed to establish a secure connection between two computers, S-HTTP is designed to send individual messages securely. Both protocols have been submitted to the Internet Engineering Task Force (IETF) for approval as a standard.
S-HTTP was developed by Enterprise Integration Technologies (EIT), which was acquired by Verifone, Inc. in 1995.