What is a digital signature?

A digital signature is indeed an encrypted code that is used for verifying the identity of the sender and ensuring the integrity of a message or document during electronic transactions. It utilizes public key cryptography, where a unique code is generated based on the content of the message and the sender's private key. This code can then be validated using the sender's public key, confirming both the identity of the sender and that the content has not been altered during transmission.

This process is crucial in establishing trust in electronic communications, especially in environments where security and authenticity are paramount, such as in online banking, contract management, and secure email exchanges.

Other options do not accurately represent what a digital signature is: an identifier for network devices refers to methods of recognizing devices on a network; data compression involves reducing the size of files; and tracking data usage pertains to monitoring how much data is consumed or transferred, none of which align with the functionalities of digital signatures.