Serial Number
Unique identifier for this certificate
The Serial Number is a unique identifier assigned to each SSL certificate by the issuing Certificate Authority (CA). No two certificates from the same CA should ever have the same serial number, making it a critical field for certificate identification and management. The serial number is typically displayed as a hexadecimal string and is used for various purposes including certificate revocation, tracking, and auditing. When a certificate needs to be revoked due to compromise or other security concerns, the CA adds the certificate's serial number to the Certificate Revocation List (CRL) or Online Certificate Status Protocol (OCSP) responses. This allows browsers and other applications to check if a certificate has been revoked. The serial number format and length can vary between CAs, but it must be unique within each CA's certificate database. This field is essential for certificate lifecycle management and security monitoring.