Future Business Leaders of America (FBLA) Cybersecurity Practice Test

What does non-repudiation ensure?

1. A party cannot deny the authenticity of their signature

2. All communications are publicly accessible

3. Users can change their signatures at will

4. Messages can be altered after sending

The correct answer is: A party cannot deny the authenticity of their signature

Non-repudiation is a critical concept in cybersecurity and data integrity that ensures a party in a communication cannot deny the authenticity of their signature or the message they sent. This means that if a user digitally signs a document or a message, they cannot later claim they did not sign it or that the message was not sent by them. This is typically achieved through the use of cryptographic techniques, such as digital signatures, which provide a way to verify the sender's identity and maintain the integrity of the message. The other options do not align with the concept of non-repudiation. Public accessibility of communications does not ensure that a sender cannot deny sending a message. Allowing users to change their signatures at will undermines the trust and accountability that non-repudiation aims to provide. Lastly, the ability to alter messages after sending would compromise both integrity and authenticity, making it impossible to assert non-repudiation since the original message could be tampered with. Therefore, ensuring that a party cannot deny the authenticity of their signature is the core aspect of non-repudiation.