SSL/TLS Glossary

Understand certificate and web encryption terminology.

SSL/TLS secures communications on the web. But the terminology can be confusing: SSL vs TLS, DV vs EV, OCSP vs CRL... This glossary clarifies essential concepts.

Whether you're setting up your first certificate or troubleshooting a handshake problem, this glossary helps you understand what's happening.

seo.glossaire_ssl.basics_title

SSL (Secure Sockets Layer) - SSL (Secure Sockets Layer)
TLS (Transport Layer Security) - TLS (Transport Layer Security)
HTTPS - HTTPS
Certificate Authority (CA) - CA (Certificate Authority)

seo.glossaire_ssl.cert_types_title

DV (Domain Validation) - DV (Domain Validation)
OV (Organization Validation) - OV (Organization Validation)
EV (Extended Validation) - EV (Extended Validation)
Wildcard Certificate - Wildcard
SAN (Subject Alternative Name) - SAN (Subject Alternative Name)

seo.glossaire_ssl.technical_title

CSR (Certificate Signing Request) - CSR (Certificate Signing Request)
Private Key - seo.glossaire_ssl.term_private_key
Certificate Chain - Certificate Chain
OCSP (Online Certificate Status Protocol) - OCSP
HSTS (HTTP Strict Transport Security) - HSTS

seo.glossaire_ssl.protocols_title

TLS 1.2 - seo.glossaire_ssl.term_tls12
TLS 1.3 - seo.glossaire_ssl.term_tls13
Cipher Suite - seo.glossaire_ssl.term_cipher
PFS (Perfect Forward Secrecy) - PFS (Perfect Forward Secrecy)

Frequently Asked Questions

SSL or TLS, what's the difference?

SSL is obsolete (last version SSLv3 from 1996). TLS is the secure successor. We say "SSL" by habit but use TLS.

DV, OV, or EV, which to choose?

DV is sufficient for most sites. OV/EV are useful for companies wanting to display verified identity.

What is an incomplete chain?

Your server doesn't send intermediate certificates. Some browsers compensate, others don't.

Is Let's Encrypt as secure as a paid certificate?

In terms of encryption, yes. The difference is in identity validation (DV only) and support.

How does HSTS work?

The server sends a header telling the browser to only use HTTPS for X time. Impossible to return to HTTP.

Why do my certificates expire?

Expiration = security. It forces key rotation and domain control revalidation.

Master SSL/TLS

SSL/TLS security is fundamental to user trust. Understanding these concepts helps you properly configure and maintain your certificates.

MoniTao monitors your certificates and alerts you before expiration or in case of chain issues. Never let an expired certificate surprise your users.

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