What role does a digital signature play in network security?

A digital signature plays a critical role in network security by providing both authentication and integrity assurance for a message. When a sender digitally signs a message, they use a cryptographic algorithm to generate a unique hash of the message content, which is then encrypted with their private key. This process ensures that the recipient can verify both the origins of the message (authentication) and that the content has not been altered during transit (integrity).

When the recipient receives the message, they can use the sender's public key to decrypt the digital signature and compare the hash with their own computed hash of the message. If both hashes match, it confirms that the message is authentic and has remained intact since being signed.

This functionality is fundamental in preventing various attacks such as impersonation and tampering, making digital signatures an essential component of secure communications and transactions across networks.