The Public Key Infrastructure (PKI) is a set of hardware, software, people, policies, and procedures needed to create, manage, store, distribute, and revoke digital certificates. An executive uses…

The Public Key Infrastructure (PKI) is a set of hardware, software, people, policies, and procedures needed to create, manage, store, distribute, and revoke digital certificates. An executive uses PKI to encrypt sensitive emails sent to an assistant. In addition to encrypting the body of the email, the executive wants to encrypt the signature so that the assistant can verify that the email actually came from the executive. Which asymmetric key should be used by the executive to encrypt the signature?