Which methods are used to implement nonrepudiation?

Nonrepudiation is a principle in cybersecurity that ensures that an individual or entity cannot deny the authenticity of their signature on a document or the sending of a message that they originated. To effectively implement nonrepudiation, methods need to provide reliable evidence of the identity of the parties involved and the integrity of the messages or transactions.

Both transactional logs and digital signatures play crucial roles in achieving nonrepudiation. Transactional logs systematically record all actions and events, ensuring a traceable history of activities. This can serve as evidence to confirm specific transactions and who performed them, effectively preventing denial of actions taken.

Digital signatures, meanwhile, use cryptographic techniques to verify the authenticity of a message and the identity of the signer. A digital signature is linked uniquely to the signer and the content of the message, meaning that if the message is altered, the signature becomes invalid. This provides a strong assurance that the signature indeed comes from the claimed sender and has not been modified in transit.

By combining both transactional logs and digital signatures, a robust nonrepudiation framework is established, solidifying the integrity and accountability of communications and transactions within a system. Thus, the correct answer encompasses both methods utilized for effective nonrepudiation.