What Is a Certificate? X.509 Structure
Decode the fields inside an SSL/TLS certificate.
Welcome
An X.509 certificate binds a public key to an identity. It is the foundation of HTTPS, email encryption, and code signing. Let's decode every field.
What Problem Do Certificates Solve?
Anyone can generate an RSA key pair. Without certificates, an attacker could substitute their public key for Google's. A certificate is a CA-signed proof that a public key belongs to a specific entity.
All lessons in this course
- What Is a Certificate? X.509 Structure
- Certificate Authorities & Trust Chains
- Certificate Revocation: CRL & OCSP
- Creating Self-Signed Certs with OpenSSL