What Is an SSL Certificate?
The small file that turns http:// into https:// — and what it's actually doing behind the scenes.
Guides covering the foundations: what SSL/TLS is, how the handshake works, the cryptography underneath, and every certificate type and field you'll run into.
The small file that turns http:// into https:// — and what it's actually doing behind the scenes.
Everyone says "SSL" but almost nobody's site still uses it. Here's the naming history and why it matters.
Three validation levels, three different amounts of paperwork — and what each one actually proves to a visitor.
Every HTTPS connection starts with a negotiation that happens in milliseconds — here's every step of it, in order.
Two keys, mathematically linked, doing two completely different jobs — the concept every other SSL topic builds on.
Why your browser trusts a certificate it's never seen before, issued by a company it's never heard of.
The document that starts every certificate's life — and the one place small mistakes cause the most downstream pain.
Three certificate shapes for three different problems — and how to tell which one you actually have.
That long string of algorithm names your SSL scan report shows — decoded piece by piece.
A faster handshake, a smaller attack surface, and a protocol that finally removed its own legacy baggage.
A DNS record type that names exactly which certificate authorities are permitted to issue for your domain.
Three certificate authorities now issue free, automated certificates via the same ACME protocol — what actually differs between them.
A mechanism for changing an already-established TLS connection's parameters mid-session — and the vulnerability that led to it being redesigned.
A certificate extension that makes OCSP stapling mandatory rather than optional — and why adoption never really took off.