prevents users from denying their participation in a transaction or communication and ensures no entity can claim a transaction didn't happen when it did, or vice versa

• A. Nonrepudiation
• B. Network Monitor
• C. Numbering System (Binary)
• D. Network ID

Answer: (A)

Nonrepudiation ensures that a party in a digital interaction cannot deny their involvement or the occurrence of a transaction. It provides proof that something happened and who was involved, using mechanisms such as digital signatures, secure hashes, and time-stamped logs backed by trusted authorities. When someone signs a message with their private key, others can verify the signature with the corresponding public key and be confident the message hasn’t been altered. Combined with tamper-evident logs or receipts, this creates binding evidence of both the origin and the timing of the transaction, making it difficult for either party to dispute participation or the event itself. This is why it’s the right concept here: it directly addresses the ability to neither deny involvement nor claim that a transaction didn’t happen.

Other options describe different ideas that don’t provide this binding proof. A network monitor watches traffic but doesn’t establish a verifiable, nonrepudiable link between a participant and a transaction. A numbering system (binary) is just a way of encoding data, not a mechanism for proving authorship or participation. A network ID identifies a network segment, not the parties involved in a specific transaction.