Public key infrastructure

A public key infrastructure (PKI) is a set of roles, policies, hardware, software and procedures used to create, manage, distribute, use, store and revoke digital certificates and manage public-key cryptography set-ups. The purpose of a PKI is to facilitate the secure storage and/or transfer of information for activities such as e-commerce, internet banking and confidential email, where passwords are an inadequate method of authentication, and more rigorous proofs are required to confirm the identities of the parties involved, and to validate the information.

Source: Wikipedia — Public key infrastructure (CC BY-SA 4.0)