August 6th, 2014 Google announced that sites using strong encryption HTTPS by default would get top priority in page PageRank. Google is did this to promote security on the web. HTTPS not only ensures the identity of the site but also provides end to end communication with the site. No one can intercept any of the information you share with the site, including passwords. This does not mean that someone (your Internet service provider) can’t tell which sites you use.
WordPress.com has partnered with the Let’s Encrypt project to enabled every site hosted there to have strong encryption including those with custom domains. This is huge for WordPress.com users. One more reason to consider them for a serious WordPress host.