For a few years now, Google has been actively encouraging the website owners to switch to HTTPS, a more secure version of the HTTP protocol. “S” stands for “security”, signifying the encrypted communication taking place between the client browser and the visited website.
Googlers lead the way by switching all of their major services/products (Google Search, Gmail, Youtube and others) to HTTPS for improved security. In August of 2014, they’ve officially announced the change to Google ranking algorithm that will give preference to websites with secure/encrypted connection. A major initiative, called HTTPS Everywhere was announced as well.
SEO, The Website Owners Series, Website Security