Definition
Public Key Infrastructure, or PKI, is a system of hardware, software, policies, and procedures used to create, manage, distribute, use, store, and revoke digital certificates and manage public key encryption. It establishes trust by binding public keys with respective user identities through a trusted third party, the Certificate Authority (CA). PKI enables secure communication and data integrity by providing authentication, encryption, and non-repudiation. This infrastructure works by issuing digital certificates that verify the identity of individuals, devices, or organizations, allowing for secure online transactions and communications. Understanding PKI is crucial for IT professionals responsible for cybersecurity, network security, and secure application development, as it underpins many security protocols. For example, HTTPS, which secures web browsing, relies heavily on PKI to authenticate websites and encrypt traffic. PKI is distinct from simple encryption, as it involves the management of keys and identities across a network, not just the encryption process itself. Knowledge of PKI is frequently tested in cybersecurity certifications like CompTIA Security+ and CySA+.