CompTIA CASP+ Practice Test 2026 - Free CASP+ Practice Questions and Study Guide

The correct answer is the practice of using a digital signature. Digital signatures provide non-repudiation due to their cryptographic nature, which verifies the authenticity of the sender and ensures that the message has not been altered in transit. When a sender applies their private key to a document or email, it creates a unique signature. The recipient can then use the sender’s public key to verify that the signature is valid, confirming the sender’s identity and that the content remained unchanged. This ability to verify origin and integrity is essential for non-repudiation.

While digital signatures do contribute to securing communications, they do not encrypt the contents of messages. If protection against network sniffers is a priority, additional layers of security, such as transport encryption, would also be deployed. Transport encryption protocols (like TLS) focus on encrypting the actual content of communications, making them unreadable to unauthorized interceptors. In contrast, firewalls regulate traffic and VPNs create secure tunnels for data transit, but neither addresses non-repudiation directly as digital signatures do.

In summary, a digital signature ensures that a message can be confidently attributed to its sender, thus establishing non-repudiation, while also promoting message integrity, which is vital in communications where confidentiality