A registration authority (RA) is responsible for processing digital certificate requests received from subscribers. The RA firstly checks that requests are valid and comply with the certification practice statement and relevant certificate policy. It then authenticates the identity of the user in accordance with any requirements in the certification practice statement and certificate policy. Once satisfied, the RA forwards the request to the certification authority to sign and issue a digital certificate to the intended certificate holder.

The quality of the registration process determines the level of trust that can be placed in the digital certificates.