In PKI, which item binds a public key to an identity by means of a trusted certificate?

In PKI, which item binds a public key to an identity by means of a trusted certificate?

• A. Public key
• B. Digital certificate
• C. Private key
• D. CRL

Answer: (B)

A digital certificate binds a public key to an identity in PKI. It includes the subject’s identity information and the public key, along with the issuer (a Certificate Authority), validity period, and a digital signature created by the CA with its private key. Anyone can verify that signature using the CA’s public key, proving that the public key actually belongs to that identity. The public key alone doesn’t prove identity, the private key is the secret counterpart used for cryptographic operations, and a certificate revocation list is only for noting revoked certificates, not binding identity to a key.

A digital certificate binds a public key to an identity in PKI. It includes the subject’s identity information and the public key, along with the issuer (a Certificate Authority), validity period, and a digital signature created by the CA with its private key. Anyone can verify that signature using the CA’s public key, proving that the public key actually belongs to that identity. The public key alone doesn’t prove identity, the private key is the secret counterpart used for cryptographic operations, and a certificate revocation list is only for noting revoked certificates, not binding identity to a key.