Question

Suppose a CA contains Bob's certificate, which binds Bob's public key to Bob. This certificate is signed with:

1) The CA's private key;
2) Bob's private key;
3) Bob's public key;
4) The CA's public key;

Answer 1

A digital certificate that binds Bob's public key to his identity is signed with the CA's private key, allowing anyone with the CA's public key to verify the certificate's authenticity.

Step-by-step explanation:

The student is asking about digital certificate authentication in the context of public key infrastructure (PKI). When a Certificate Authority (CA) issues a certificate, it binds an entity's public key to its identity--in this case, Bob's public key to Bob. The certificate is signed with the CA's private key to ensure authenticity. Anyone with access to the corresponding CA's public key (which is publicly available) can verify the signature. This is a key part of how trust is established in digital communications.