(ISC)2 Certified in Cybersecurity Practice Exam

What principle does non-repudiation support in transactions?

1. Acknowledgment by third parties

2. Verification of data authenticity

3. Ensuring accountability and traceability

4. Privacy of communication

The correct answer is: Ensuring accountability and traceability

Non-repudiation is a fundamental principle in cybersecurity and digital transactions that ensures accountability and traceability. It guarantees that once a transaction has been committed, the parties involved cannot deny their involvement or the authenticity of that transaction. This is crucial in both legal and security contexts, as it provides evidence that an action was taken by a specific user or system. For example, in a financial transaction, if a user sends money, non-repudiation ensures that the user cannot later claim they did not approve the transaction. This is typically achieved through mechanisms such as digital signatures or encryption, which provide a secure way to validate the identity of the parties involved and the integrity of the data being transmitted. The other options touch on important concepts but do not encapsulate the core function of non-repudiation. While acknowledgment by third parties might involve validation, it does not inherently enforce accountability. Verification of data authenticity is related but focuses more on data integrity rather than the denial of participation. Privacy of communication addresses the confidentiality of the messages exchanged rather than the assurance that a transaction occurred and can be traced back to the responsible party.