Non-Repudiation assures that sender of the message cannot deny the validity of the message sent.

Non-Repudiation assures that sender of the message cannot deny the validity of the message sent.

• A. Attestation
• B. Non-Repudiation
• C. Privacy
• D. Confidentiality

Answer: (B)

Non-repudiation is the assurance that a sender cannot deny having sent a message or performed an action. This relies on proving who issued the message and that it hasn’t been altered. In practice, digital signatures are the core mechanism: the sender signs the message with a private key, and anyone can verify the signature with the sender’s public key. Because the signature is uniquely tied to the signer and the message, the signer cannot later repudiate sending it; there’s verifiable evidence of origin and integrity. Additional elements like timestamps and audit logs strengthen accountability. Attestation is about confirming that a claim is true, often by a trusted party, but it doesn’t inherently bind a sender to a specific message. Privacy and Confidentiality protect information from unauthorized access, not the sender’s denial of having sent a message.

Non-repudiation is the assurance that a sender cannot deny having sent a message or performed an action. This relies on proving who issued the message and that it hasn’t been altered. In practice, digital signatures are the core mechanism: the sender signs the message with a private key, and anyone can verify the signature with the sender’s public key. Because the signature is uniquely tied to the signer and the message, the signer cannot later repudiate sending it; there’s verifiable evidence of origin and integrity. Additional elements like timestamps and audit logs strengthen accountability.

Attestation is about confirming that a claim is true, often by a trusted party, but it doesn’t inherently bind a sender to a specific message. Privacy and Confidentiality protect information from unauthorized access, not the sender’s denial of having sent a message.