Which of the following occurs in a PKI environment?

A.
The RA creates the certificate, and the CA signs it.

B.
The CA signs the certificate.

C.
The RA signs the certificate.

D.
The user signs the certificate.

Explanation:
B: A certificate authority (CA) is a trusted organization (or server) that maintains and issues digital certificates. When a person requests a certificate, the registration authority (RA)
verifies that individual’s identity and passes the certificate request off to the CA. The CA constructs the certificate, digitally signs it, sends it to the requester, and maintains the
certificate over its lifetime. The CA digitally signs it so that the receiver can verify that the certificate came from that specific CA. The CA digitally signs the certificate with its private key,
and the receiver verifies this signature with the CA’s public key.
A is incorrect because the registration authority (RA) does not create the certificate; the certificate authority (CA) creates it and signs it. The RA performs the certification registration
duties. The RA establishes and confirms the identity of the individual requesting the certificate, initiates the certification process with a CA on behalf of an end user, and can perform
certificate life-cycle management functions. The RA cannot issue certificates but can act as a broker between the user and the CA. When users need new certificates, they make
requests to the RA, and the RA verifies all necessary identification information before allowing a request to go to the CA.
C is incorrect because the registration authority (RA) does not sign the certificate. The certificate authority (CA) signs the certificate. The RA validates the user’s identity and then
sends the request for a certificate to the CA.
D is incorrect because the user does not sign the certificate. In a PKI environment, a user’s certificate is created and signed by the certificate authority (CA). The CA is a trusted third
party that generates and maintains user certificates, which hold their public keys. The certificate is digitally signed to provide confidence to others that the certificate was created by
that specific CA.