It does not matter whether you created your blog site or website under a sub-domain name or a blog site or website with your own domain name - what is important is that your blog site or your website is a secured and friendly site for Search Engines Crawlers and to your would-be visitors. Search Engines Crawlers would rate your blog site or website through the site's security indicators if it is secured, not secured or it is dangerous site at the time these Engines Crawlers have spotted your site.
See the below screen shot of symbols that online crawlers have used to identify your site and to alert your site's visitors if your site's connection is secure.
See the below screen shot of symbols that online crawlers have used to identify your site and to alert your site's visitors if your site's connection is secure.