The Free On-line Dictionary of Computing (30 December 2018):

Secure Sockets Layer

    (SSL) A protocol designed by
   Netscape Communications Corporation to provide secure
   communications over the Internet using asymmetric key
   encryption.  SSL is layered beneath application protocols
   such as HTTP, SMTP, Telnet, FTP, Gopher and NNTP
   and is layered above the connection protocol TCP/IP.  It is
   used by the HTTPS access method.

   (2007-05-25)