WebPKI, or the public Web Public Key Infrastructure, is the system browsers and operating systems use to decide whether a TLS certificate should be trusted. Certificate authorities (CAs) issue certificates and digitally sign them; software checks the signature chain back to a trusted root and verifies details such as the site name and certificate validity. This is what lets users establish encrypted connections with websites while checking that the site’s identity is supported by a trusted CA.
WebPKI matters because failures in a CA’s systems or key handling can undermine certificate issuance and affect services that rely on those certificates. In attacks, criminals may exploit misissued certificates or compromised signing keys to impersonate services; defenders monitor certificate issuance, protect CA keys, and plan for certificate replacement or changes in trust. If confidence in a CA’s processes is in doubt, organizations should inventory affected certificate chains and prepare resilient renewal paths.