Ssl certificates
From wikinotes
SSL certificates are essentially verified public keys as a part of an asymetric key authentication system.
All that SSL certificates offer on top of regular asymetric key is a form of recognition that the server is who it says it is.
You may also be interested in openssl or libressl.
Notes
SSL certificate intro SSL certificate creation SSL certificate authority SSL certificate hardening
Related
openssl toolkit for SSL/TLS cryptography libressl toolkit for SSL/TLS cryptography (forked by OpenBSD project) certbot free/automated SSL certificates
