What is a digital certificate primarily used for?

A digital certificate is primarily used to prove ownership of a public key. This is a critical function in establishing trust in digital communications. When a digital certificate is issued, it acts as a guarantee from a trusted third party, known as a Certificate Authority (CA), that the public key contained within the certificate belongs to the entity it claims to represent. This verification is essential for secure communications, as it ensures that parties can trust one another's identities and that they are indeed communicating with the intended entity.

The concept of ownership is vital because public key cryptography relies on the assumption that the public key is indeed associated with the correct owner. Without a means to verify this, the security provided by cryptographic systems could be compromised. This verification process prevents impersonation and man-in-the-middle attacks, making digital certificates a foundational aspect of secure data transmission over the internet.

In contrast, the other options reflect functionalities or purposes that are either related but do not capture the primary purpose of a digital certificate. For instance, while digital certificates can be part of enabling secure financial transactions, their main goal is identity verification, not the transaction itself. Monitoring network traffic is a separate security function that does not involve digital certificates, and while encryption is a significant aspect of secure communications,