We recently migrated from 'http' to 'https' for all our blogs. This is a move I badly need to make so that we can make our blogs future-proof. Google officially said this:
"Over the past few months, we’ve been running tests taking into account whether sites use secure, encrypted connections as a signal in our search ranking algorithms. We've seen positive results, so we're starting to use HTTPS as a ranking signal." (via Official Google Webmaster Central Blog)
So it's a wise move to start doing this now. When people see the term(s) like 'SSL' or 'HTTPS', they think they need to invest a lot of money, even I was worried about this initially, but we do have some best & trusted free SSL providers.
So, this is one we are using for our Slashsquare blog network, including this forum powered by Discourse. Let's Encrypt is also recommended & used by popular brands like WordPress and Bitly.
Yes! The popular free CDN provider also has a free SSL (https) option for you. You can log into your account and find the option to activate and proceed further.
I haven't used this one, but it's widely recommended by our HBB group members, so adding this here. But nevertheless, they generate certificates using Let's Encrypt ACME server by using domain validation.
These 3 SSL certificate providers are the ones we know about, is there any other names you want us to add here?
In our previous post, we discussed the difference between free SSL and paid/premium SSL certificates, you can look into that before deciding as well.