Certificates are pretty much everywhere nowadays: they’re used on most web servers for TLS (what SSL should properly be called, though the old name is stickier than was anticipated), Dartmouth is soon going to move eduroam authentication to certificates instead of usernames and passwords, certificates can be used to encrypt email communication - and that’s just three common use cases among many. In this essay blog post, we’ll explore the basics of what certificates are and how they actually work....