How does public key infrastructure (PKI) work?

Public Key Infrastructure (PKI) is a system that manages digital keys and certificates to enable secure communication over a network. It uses a pair of cryptographic keys – a public key that is widely distributed and a private key that is kept secret. PKI facilitates secure communications by providing three main functions:

1. Authentication: PKI verifies the identity of parties involved in communication by using digital certificates. These certificates are issued by a trusted third party, known as a Certificate Authority (CA), which confirms the association between a public key and the entity it belongs to.

2. Confidentiality: PKI ensures that data exchanged between parties is protected from unauthorized access through encryption. The public key encrypts the data, which can only be decrypted by the corresponding private key, ensuring that only the intended recipient can access the information.

3. Integrity: PKI guarantees that data transmitted between parties is not altered during transit. Digital signatures generated using private keys allow recipients to verify that the data they receive is authentic and has not been tampered with.

Overall, PKI establishes a secure communication framework by enabling trusted authentication, encryption for confidentiality, and integrity verification, thus safeguarding data exchanged over networks.