What is the primary function of a Certification Authority (CA) in a Public Key Infrastructure (PKI)?

The primary function of a Certification Authority (CA) in a Public Key Infrastructure (PKI) is to issue digital certificates. A CA is a trusted entity that creates and signs digital certificates, which are used to associate a public key with the identity of an individual, organization, or device. This signing process relies on the CA's private key to validate the authenticity of the certificate, ensuring that the public key contained therein genuinely belongs to the entity it claims to represent.

By issuing these certificates, the CA provides a critical layer of trust in online communications, enabling users to verify the identity of the parties they are communicating with and establishing secure connections using encryption. This function is essential for a variety of applications, including secure web browsing (HTTPS), email security (S/MIME), and code signing.

While the other functions mentioned, such as verifying certificate contents, distributing certificates, and storing archived information, are relevant to the overall functioning of a PKI, they do not encapsulate the primary role of the CA. The issuance of digital certificates is central to the trust framework established by PKI systems.