Which of the following would effectively verify the originator of a transaction?

A. Using a secret password between the originator and the receiver

B. Encrypting the transaction with the receivers public key

C. Using a portable document format (PDF) to encapsulate transaction content

D. Digitally signing the transaction with the sources private key

Explanation:

A digital signature is an electronic identification of a person, created by using a public key algorithm, to verify to a recipient the identity of the source of a transaction and the integrity of its content. Since they are a shared secret between the user and the system itself, passwords are considered a weaker means of authentication. Encrypting the transaction with the recipients public key will provide confidentiality for the information, while using a portable document format(PDF) will probe the integrity of the content but not necessarily authorship.