What is a Digital Certificate used for?

A digital certificate is primarily used to prove ownership of a public key. It serves as a credential issued by a trusted authority, often referred to as a Certificate Authority (CA). The digital certificate includes information about the entity to which it is issued, the public key itself, and the digital signature of the CA, which vouches for the authenticity of the certificate.

This function is crucial in various security protocols, such as Secure Sockets Layer (SSL) and Transport Layer Security (TLS), where it establishes a secure channel between clients and servers by ensuring that the public key presented belongs to the legitimate entity and not an impersonator. This validation is key to the secure exchange of information over networks, as it mitigates risks such as man-in-the-middle attacks.

Understanding this function emphasizes how critical digital certificates are in establishing trust in digital communications and securing transactions. In contrast, the other options pertain to different functions: validating software licenses, encrypting data transmissions, and tracking user activities, which do not encapsulate the primary role of digital certificates in verifying public key ownership and facilitating secure communications.