Nonrepudiation is the ability to prevent or deny the parties involved in an electronic transaction from disputing or rejecting the validity or authenticity of the transaction. Nonrepudiation ensures that the parties cannot claim that they did not send or receive the transaction, or that the transaction was altered or tampered with.

The tool that helps ensure compliance with a nonrepudiation policy requirement for electronic transactions is digital signatures, which are the electronic equivalents of handwritten signatures that are used to verify the identity and integrity of the sender and the content of the transaction. Digital signatures are generated by applying a cryptographic algorithm to the transaction, using the sender’s private key, which is a secret and unique code that only the sender knows and possesses. The digital signature can be verified by the receiver or any third party, using the sender’s public key, which is a code that is publicly available and corresponds to the sender’s private key. The digital signature can prove that the transaction was sent by the sender, and that the transaction was not altered or tampered with during the transmission.

The other options are not the tools that help ensure compliance with a nonrepudiation policy requirement for electronic transactions, because they do not provide the same level ofverification and validation that digital signatures provide, and they may not be sufficient or effective to prevent or deny the parties from disputing or rejecting the transaction.

Encrypted passwords are the passwords that are converted into a secret or unreadable form, using a cryptographic algorithm, to protect them from unauthorized access or disclosure. Encrypted passwords can help to ensure the confidentiality and security of the passwords, but they are not the tools that help ensure compliance with a nonrepudiation policy requirement for electronic transactions, because they do not verify the identity and integrity of the sender and the content of the transaction, and they may not prevent or deny the parties from disputing or rejecting the transaction.

One-time passwords are the passwords that are valid or usable for only one session or transaction, and that are randomly generated or derived from a dynamic factor, such as time, location, or device. One-time passwords can help to enhance the security and authentication of the parties involved in the transaction, but they are not the tools that help ensure compliance with a nonrepudiation policy requirement for electronic transactions, because they do not verify the identity and integrity of the sender and the content of the transaction, and they may not prevent or deny the parties from disputing or rejecting the transaction.

Digital certificates are the electronic documents that contain the information and credentials of the parties involved in the transaction, such as their name, public key, expirationdate, etc., and that are issued and signed by a trusted authority or entity, such as a certificate authority or a digital signature provider. Digital certificates can help to establish and confirm the identity and trustworthiness of the parties involved in the transaction, but they are not the tools that help ensure compliance with a nonrepudiation policy requirement for electronic transactions, because they do not verify the identity and integrity of the sender and the content of the transaction, and they may not prevent or deny the parties from disputing or rejecting the transaction. References =

ISACA, CRISC Review Manual, 7th Edition, 2022, pp. 40-41, 47-48, 54-55, 58-59, 62-63

ISACA, CRISC Review Questions, Answers & Explanations Database, 2022, QID 197

CRISC Practice Quiz and Exam Prep