X.509 Certificates
A standard defining the format of public key certificates used in SSL/TLS for secure communications.
Understanding X.509 Certificates
X.509 is a widely used standard for public key certificates, which authenticate entities in secure communications. These certificates verify identities and enable SSL/TLS encryption for secure data transmission over the internet.
Structure of an X.509 Certificate
An X.509 certificate contains:
Subject – The entity being verified (e.g., a website or user).
Issuer – The Certificate Authority (CA) that issued the certificate.
Public Key – Used for encryption and authentication.
Validity Period – Start and expiration dates.
Digital Signature – Ensures the certificate's authenticity.
Common Uses of X.509 Certificates
SSL/TLS Encryption – Secure HTTPS communication between users and websites.
Digital Signatures – Verify software integrity and email authenticity.
User Authentication – Used in VPNs and secure login systems.
Security Concerns and Mitigation
Certificate Expiry – Regularly update certificates to avoid disruptions.
Man-in-the-Middle (MITM) Attacks – Use Certificate Pinning to prevent interception.
Compromised Certificate Authorities – Rely on trusted and well-established CAs.