What is primarily the function of a digital signature?

The primary function of a digital signature is to verify the authenticity of data. Digital signatures serve as a means of ensuring that the information has not been altered and that it truly comes from the claimed sender. When a digital signature is created, a unique hash of the data is generated, and this hash is then encrypted using the sender’s private key. The recipient can subsequently decrypt the hash using the sender's public key, allowing them to confirm the integrity of the data and the identity of the sender.

This process enhances trust in digital communications, as it provides a way to confirm that the content of a message or document is genuine. Digital signatures are widely used in various applications, including email verification, software distribution, and secure transactions.

The other options entail different functions: generating symmetric keys is related to cryptographic key management, encrypting data involves protecting the confidentiality of information, and creating a backup involves data redundancy and recovery—a different focus altogether.