What is SSL/TLS?

SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) are cryptographic protocols that secure communication between your browser and a web server — the "S" in HTTPS.

How the TLS Handshake Works

1. Client Hello — Browser sends supported cipher suites and TLS version
2. Server Hello — Server responds with chosen cipher and its certificate
3. Certificate Verification — Browser checks the cert against trusted CAs
4. Key Exchange — Both sides generate a shared session key
5. Encrypted Session — All data is now encrypted with the session key

Certificate Authorities (CAs)

CAs are trusted organizations that issue SSL certificates. They verify that the certificate requester controls the domain. Major CAs include Let's Encrypt (free), DigiCert, and Sectigo.

Types of Certificates

• DV (Domain Validated) — Basic, verifies domain control only
• OV (Organization Validated) — Verifies the organization's identity
• EV (Extended Validation) — Highest level, rigorous verification

Try It

Use our SSL Checker tool to inspect any website's certificate details.