Which of the following best represents the principle of nonrepudiation?

The principle of nonrepudiation ensures that a party in a communication or transaction cannot deny the authenticity of their signature or the sending of a message. Digital signatures are a fundamental technology that provides proof of the origin, identity, and status of an electronic document. They enable the recipient to verify that the sender cannot subsequently claim that they did not send the message or approve a transaction.

By using cryptographic techniques, digital signatures provide a mechanism to bind the identity of an individual to a message securely. This binding makes it practically impossible for the signer to refute the signed message later, thus upholding the principle of nonrepudiation. In contexts where accountability is crucial, such as in legal documents or financial transactions, the presence of a digital signature establishes a clear record that can be used as evidence of both intent and authorization.

Other options, while relevant to the broader field of information security, do not directly address the principle of nonrepudiation. Encryption of data focuses on securing information to prevent unauthorized access but does not provide proof of identity or origin. Physical access control relates to restricting access to physical locations or assets rather than managing identities in communications. Network monitoring involves observing network traffic for malicious activity, which does not pertain to establishing nonrepudi