A digital signature included in an e-mail is used to __________.

A digital signature included in an e-mail serves the primary purpose of validating the sender. When a sender applies a digital signature to an email, they are essentially attaching a cryptographic stamp that confirms their identity. This technique uses asymmetric encryption, where the sender encrypts the signature using their private key. Anyone receiving the email can then validate the signature using the sender's public key. This process ensures that the content has not been altered during transmission and verifies that the message was indeed sent by the claimed sender.

This validation is crucial in maintaining the integrity of electronic communications, especially in scenarios where authenticity and non-repudiation are vital, such as legal documents, financial transactions, or sensitive information exchanges. The inclusion of a digital signature assures the recipient that the message genuinely comes from the alleged source and was not tampered with.