What is a primary use of digital certificates?

Digital certificates play a critical role in establishing trust within digital communications, and one of their primary uses is to authenticate the sender of a message. By verifying the identity of the sender, digital certificates ensure that the communication is coming from a legitimate source, rather than an impersonator or malicious actor. This authentication process is particularly important in scenarios such as email communication, secure websites, and digital signatures, where the integrity and authenticity of the sender need to be verified to prevent fraud and ensure secure transactions.

Digital certificates are issued by trusted entities known as Certificate Authorities (CAs). Each certificate contains a public key, along with information about the identity of the certificate holder, which can be used by the recipient to verify that the public key belongs to the claimed sender. This helps establish a chain of trust and allows for secure and authenticated communications over potentially insecure channels.

In the context of the other options, while encrypting data at rest is an important function of cryptographic techniques, it is not a primary function of digital certificates themselves. Improving system performance and monitoring network traffic are also not directly related to the primary role of digital certificates, which centers around authentication and establishing trust.