public key infrastructure

Core framework required to provide public key cryptography and digital signature services for electronic commerce transactions via the Internet. A PKI provides confidentiality (to keep information private), integrity (to prove it has not been altered), authentication (to prove the identity of a person or a computer application), and non-repudiation (to prevent information being disowned). SET is a form of PKI.

A PKI consists of a certification authority (CA) for the issue of digital certificates, a certificate repository (or directory) to allow applications to obtain certificates, a certificate revocation system, a key back-up and recovery system (not the same as key escrow), support for non-repudiation of digital signatures, automatic key update, management of key histories, validation of certificates issued by another CA, and time-stamping to identify when a transaction took place, as well as software to support all of these activities.