A systems administrator needs a server that can accept requests for digital certificates. Which of the following should the sysadmin set up?

Setting up a Registration Authority (RA) is appropriate for a systems administrator looking to handle requests for digital certificates. The RA plays a crucial role in the public key infrastructure (PKI) by validating the identity of users or devices requesting certificates before these requests are forwarded to a Certificate Authority (CA). This means the RA acts as a mediator, providing an essential layer of authentication to ensure that only legitimate requests are processed.

An RA can issue certificates, but its primary function is to accept and validate requests. It is responsible for ensuring that the requester is who they claim to be, which is a critical step in the certificate issuance process. Once the RA has authenticated the user's identity, it can then pass the validated request to a CA, which ultimately generates the digital certificate.

In contrast, the CA is responsible for the actual issuance of certificates and managing the certificate lifecycle, but it relies on the RA to handle the initial request and associated identity verification. While a CA or any subordinate or intermediate CAs play significant roles in the broader certificate management framework, establishing an RA specifically addresses the need for processing incoming requests for digital certificates effectively.