Syngress book question....Security+ prep

gwamaka

I was going through Syngress book end of chapter questions and on Cryptography basics I came across this question:

You receive a digitally signed e-mail message. Which of the following actions can the author take?
A. Send you another unsigned message
B. Dispute the wording in parts of the message
C. Claim the message was not sent
D. Revoke the message

May be I am reading too much into the question, but could someone break it down for me of what the question is asking about?

dynamik

One of the benefits of signing is non-repudiation. Therefore, the content can't be disputed, and he can't claim the message wasn't sent by him. D is incorrect because you can't revoke an email; I don't think that is anything specific to cryptography. Finally, A is obviously a correct option because there is no reason he couldn't send you another unsigned email. I think you're just confused because A seems out of place, which it is. I don't think that's a very good question, so I wouldn't worry about it.