What elements does a digital certificate have?

• A. A private key, certificate subject, and encryption method.
• B. A public key, certificate authority identification, and user/server information.
• C. A certificate revocation list, key usage, and policy OID.
• D. A signature, expiration date, and issuer contact.

Answer: (B)

Digital certificates bind a public key to an identity and are issued by a trusted authority. The essential pieces are the public key, information identifying the subject (the user or server), and the issuer’s identity (the certificate authority) so others can verify who the key belongs to and trust the certificate. That’s why the best answer lists a public key, CA identification, and user/server information. The private key is kept secret by the owner and is not part of the certificate, and an encryption method isn’t a standard certificate field. Additional items like revocation lists or certain extensions exist, but they’re not the fundamental elements that define what a certificate is. A signature and expiration date are part of the certificate, but issuer contact isn’t a standard field, making that option less accurate overall.