PKI stands for Public Key Infrastructure. It is a system of technologies, policies, and procedures used to manage digital certificates and public-private key pairs. PKI provides a secure way to authenticate the identity of individuals, devices, and organizations in a networked environment.
In a PKI, a trusted third-party entity called a Certificate Authority (CA) issues digital certificates that bind a public key to a specific entity. These certificates are used to verify the authenticity and integrity of digital communications and transactions.
The main components of a PKI include:
1. Certificate Authority (CA): A trusted entity that issues and manages digital certificates.
2. Public Key: A cryptographic key that is publicly shared and used for encryption and verifying digital signatures.
3. Private Key: A cryptographic key that is kept secret and used for decryption and creating digital signatures.
4. Digital Certificate: A digitally signed document that binds a public key to an entity’s identity. It contains information such as the entity’s name, public key, and the CA’s digital signature.
5. Certificate Revocation: The process of invalidating a digital certificate before its expiration date. This can happen if the private key is compromised or if the entity’s information changes.
PKI is widely used in various applications, including secure email communication, secure web browsing (HTTPS), digital signatures, and secure access to networks and systems. It provides a foundation for establishing trust and ensuring the confidentiality, integrity, and authenticity of digital communications.