EFF Let’s Encrypt

Let’s Encrypt is a free, automated, and open Certificate Authority provided by the EFF to further internet encryption.

Unlike digicert, godaddy, instantssl or whomever you have been purchasing your SSL certificate from in the past Let’s Encrypt will issue a free certificate.

Unlike these other providers the certificate is only valid for 90 days BUT they have software that automates the process of renewal so that once it’s setup it keeps the certificate updated and it just works!

https://letsencrypt.org/