What does a Certificate Authority do in securing website communications?

What does a Certificate Authority do in securing website communications?

• A. Verifies that a website's public key actually belongs to that site
• B. Encrypts all traffic between browser and server
• C. Stores user passwords for the site
• D. Issues domain registrations

Answer: (A)

The concept being tested is how Certificate Authorities establish trust in website communications by binding a public key to a specific domain. A CA verifies that the entity applying for the certificate actually controls the domain and then issues a certificate that includes the site’s public key and domain name, signed by the CA. When a browser connects, it checks the certificate against trusted CAs, confirms it is valid and matches the site, and then uses the public key to establish an encrypted channel. So the CA’s role is to verify that a website’s public key truly belongs to that site, enabling trust in the TLS handshake. Encryption of traffic is handled by TLS using the certificate, but the CA does not itself encrypt all traffic. Storing user passwords and registering domains are not functions of a CA; password storage is the site's responsibility, and domain registrations are handled by domain registrars.

The concept being tested is how Certificate Authorities establish trust in website communications by binding a public key to a specific domain. A CA verifies that the entity applying for the certificate actually controls the domain and then issues a certificate that includes the site’s public key and domain name, signed by the CA. When a browser connects, it checks the certificate against trusted CAs, confirms it is valid and matches the site, and then uses the public key to establish an encrypted channel. So the CA’s role is to verify that a website’s public key truly belongs to that site, enabling trust in the TLS handshake. Encryption of traffic is handled by TLS using the certificate, but the CA does not itself encrypt all traffic. Storing user passwords and registering domains are not functions of a CA; password storage is the site's responsibility, and domain registrations are handled by domain registrars.