Certificate Lifecycle Management

The certificate lifecycle begins with key generation and certificate signing request (CSR) creation. Proper key generation requires a cryptographically secure random number generator and sufficient key strength for the intended lifetime. The CSR contains the public key and identifying information, signed with the corresponding private key to prove possession. Organizations must protect private keys throughout the certificate lifecycle, as compromise enables attackers to impersonate the legitimate server.

Certificate issuance follows successful validation, with the CA creating a certificate containing the verified information and their signature. Modern issuance processes increasingly use automation through protocols like ACME (Automated Certificate Management Environment), enabling programmatic certificate requests and renewals. This automation reduces human error and enables more frequent certificate rotation, improving security through limited exposure windows.

Installation and configuration require careful attention to security and compatibility. Servers must be configured to present the complete certificate chain, enabling browsers to verify the path from the server certificate to a trusted root. Protocol versions and cipher suites must balance security with client compatibility. Additional configurations like OCSP stapling and HTTP Strict Transport Security enhance security and performance.

Renewal and replacement form ongoing responsibilities throughout the certificate lifecycle. Certificates have limited validity periods to ensure regular revalidation and enable algorithm migrations. Organizations must track expiration dates and complete renewal before certificates expire to avoid service disruptions. Automated renewal through ACME or provider APIs reduces the risk of accidental expiration, though manual processes may still be necessary for higher validation levels.