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EC-Council

312-50V11 · Question #888

Bob, your senior colleague, has sent you a mail regarding a deal with one of the clients. You are requested to accept the offer and you oblige. After 2 days. Bob denies that he had ever sent a mail. W

The correct answer is D. Non-Repudiation. Non-repudiation is the security property that prevents a party from denying a previously performed action, such as sending a message. It is the concept needed to prove Bob sent the email.

Information Security and Ethical Hacking Fundamentals

Question

Bob, your senior colleague, has sent you a mail regarding a deal with one of the clients. You are requested to accept the offer and you oblige. After 2 days. Bob denies that he had ever sent a mail. What do you want to ""know"" to prove yourself that it was Bob who had send a mail?

Options

  • AAuthentication
  • BConfidentiality
  • CIntegrity
  • DNon-Repudiation

How the community answered

(23 responses)
  • A
    9% (2)
  • B
    4% (1)
  • D
    87% (20)

Why each option

Non-repudiation is the security property that prevents a party from denying a previously performed action, such as sending a message. It is the concept needed to prove Bob sent the email.

AAuthentication

Authentication verifies identity at the time of access or login, but does not provide retrospective proof that a specific action was taken by that identity.

BConfidentiality

Confidentiality ensures data is not disclosed to unauthorized parties, which is unrelated to proving the origin of a sent message.

CIntegrity

Integrity confirms that data was not altered in transit, but does not identify or bind the message to a specific sender.

DNon-RepudiationCorrect

Non-repudiation ensures that a sender cannot credibly deny having sent a message. Digital signatures achieve this by cryptographically binding the message to the sender's private key, creating verifiable proof of origin. This is the exact scenario described - proving authorship of an already-sent email.

Concept tested: Non-repudiation via digital signatures

Source: https://csrc.nist.gov/glossary/term/non_repudiation

Topics

#non-repudiation#information security principles#email authentication#CIA triad

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