What is a digital certificate used for in cybersecurity?

A digital certificate plays a crucial role in cybersecurity by authenticating the identities of entities—such as individuals, organizations, or devices—and facilitating secure communications over networks. It is issued by a trusted third party known as a Certificate Authority (CA) and contains essential information, including the subject's public key, the CA's signature, and the expiry date of the certificate.

When a digital certificate is used, it enables parties involved in communication to verify each other's identities, thus preventing impersonation and ensuring that data transmitted is secure and encrypted. This is particularly important in establishing secure connections, such as those used in SSL/TLS for secure web browsing. The authentication process helps build trust between users and services, which is essential for conducting secure transactions online.

In contrast, the other options do not accurately represent the purpose of digital certificates: storing passwords securely does not involve digital certificates, deleting unauthorized files falls under file management and security practices, and tracking user activity pertains more to monitoring and analytics than to identity verification or secure communications.