A system of certificate authorities, digital certificates, and registration authorities that verify and authenticate parties involved in Internet transactions. Because PKIs are evolving, no single PKI or one agreed-upon standard for setting up a PKI exists. However, no one in the security field disagrees that reliable PKIs are critical for ensuring trust in online transactions if electronic commerce (known as e-commerce) is to reach its fullest potential. PKI is also known as “a trust hierarchy.”

See Also: Internet; Trust.