PKI (public key infrastructure)
Public key infrastructure (PKI) is the overall system of certificate authorities, certificates, and trust relationships, profiled for internet use in RFC 5280, that lets one party prove its identity to another using public-key cryptography without the two ever having met or exchanged a secret in advance. A client trusts a certificate not because it inspects the server's key directly, but because it can verify an unbroken chain of signatures leading from that certificate back to a root the client's operating system or browser already trusts. PKI covers more than issuance: it also defines how a certificate is revoked before its stated expiry, via a certificate revocation list or OCSP, and how a private key is protected, since PKI's entire guarantee collapses the moment a CA's or server's private key is exposed. The web's HTTPS trust model runs on these same PKI foundations.
By AdminKit team, Netbase JSC · Updated