Public Key Infrastructure (PKI) is a technology framework that supports secure communication over networks. It uses public key cryptography and digital certificates to ensure the confidentiality, integrity, and authenticity of data. In PKI, a pair of public and private keys is used, where the public key is openly shared for encrypting information, and the private key is kept secret by the receiver to decrypt the information.
The core components of PKI include Certificate Authorities (CA), Registration Authorities (RA), Certificate Revocation Lists (CRL), and Digital Certificates. Certificate Authorities are responsible for issuing and managing digital certificates to verify the identity of entities. Registration Authorities, as a subsidiary of CAs, are responsible for verifying user identities and handling certificate requests. Certificate Revocation Lists are used to record certificates that have become invalid or are no longer trusted.
PKI is widely used in applications such as secure email, Virtual Private Networks (VPNs), secure website access (like HTTPS), digital signatures, and Internet of Things (IoT) security. Through PKI, businesses and users can establish trust, ensuring the security of communication and transactions.