What does non-repudiation ensure in data transactions?

Non-repudiation is a key principle in information security that ensures that once a message is sent, the sender cannot deny having sent it. This is particularly important in data transactions because it provides accountability. By guaranteeing that the sender’s action is verifiable and undeniable, non-repudiation helps to establish trust in the communication process.

This concept often involves the use of digital signatures or encryption techniques, which provide proof of the origin and integrity of a message. In legal and business contexts, it plays a critical role in ensuring that parties involved in a transaction cannot dispute the authenticity of their communications or actions, thereby reducing the risk of fraud and ensuring that data transactions are secure and credible.

While the other options discuss aspects of data security such as availability, confidentiality, and integrity, they do not capture the essence of non-repudiation, which is specifically focused on the assurance that the sender's involvement in the transaction is undeniable.