PKI (Public Key Infrastructure) works based on the support of digital certificates, it includes the following components: Hardware, software, policy sets, certificate card issuance/revocation procedures and standards. These components work together to establish a method of exchanging information in a network environment that ensures the highest level of security for partner identity authentication.

The main task of PKI is to use public key encryption to create, manage, and revoke authentication cards. Concrete:

• Create and validate digital signatures
• Respond to the card registration of new users
• Authenticate users and distribute authentication cards to them
• Revocation of expired endorsement cards
• Generate private and public keys for client PKIs.

With the help of PKI, the security system can authenticate users in a more secure way than standard authentication (authentication through user name and password): It uses authentication cards containing the identification and public key of an exchange partner to determine their identity and validity. In addition, PKI also helps encrypt sensitive information and "sign" digital documents.

It can be said that PKI is an information technology infrastructure, it allows users on the Internet to exchange information privately and securely through the use of their own public and private key pairs. This key pair is received and shared through a trusted authorization center (CA).