Certificate Authority (CA)
An entity that issues digital certificates to authenticate users and websites.
Understanding Certificate Authorities (CA)
CAs play a crucial role in SSL/TLS encryption, ensuring that websites, applications, and services use secure connections. When a website uses HTTPS, the CA verifies its identity and issues an SSL/TLS certificate, allowing users to trust the connection. Organizations also use private CAs for internal security, securing corporate networks, emails, and software applications.
Types of Certificate Authorities
Root CA
The highest level of trust in the PKI hierarchy.
Signs and issues certificates for subordinate/intermediate CAs.
Intermediate CA
Sits between the Root CA and end-user certificates.
Adds security by preventing direct Root CA exposure.
Public vs. Private CAs
Public CAs (e.g., DigiCert, GlobalSign, Let’s Encrypt) issue certificates for public websites.
Private CAs issue certificates for corporate networks, VPNs, and internal systems.
Common Applications
SSL/TLS Certificates: Encrypts web traffic and ensures website authenticity.
Code Signing Certificates: Verifies software integrity and authenticity.
Email Encryption Certificates: Secures email communications with S/MIME.
Device Authentication: Ensures secure communication between IoT devices.