I need a security wizard here...
This question is from certification zone:
Diffie-Hellman exchange prevents what type of attack on secure
communications?
A.
Denial of service
B.
Session key cryptanalysis
C.
Replay
D.
Man-in-the-middle
Your Answer: D
Correct Choice: d
Answer Explanation
Diffie-Hellman is used in the secure exchange of information from which
session keys are generated for communications between legitimate users A
and B. It prevents man-in-the-middle attacks, in which an intruder M
lies to B, saying it is A, and lies to A, saying it is B. If A and B
accept M's statement, A and B will both send to M, and M can read or
change the information flow.
This excerpt is from Cisco's website and the Internet Protocol Journal
6/98:
* Anonymous Diffie-Hellman: The base Diffie-Hellman algorithm is
used, with no authentication. That is, each side sends its public
Diffie-Hellman parameters to the other, with no authentication.
This approach is vulnerable to man-in-the-middle attacks, in which
the attacker conducts anonymous Diffie-Hellman exchanges with both
parties.
I understand the way Diffie-Hellman works and exchanges public keys
using a mathematical formula and is vulnerable to man-in-the-middle
during the original D-H exchange. I also understand how further key
exchange for data encryption works after D-H is computed. What I'm
getting at here is what's the Cisco answer? D-H is vulnerable to
man-in-the-middle during the original exchange but protects the exchange
of the real key used for data encryption if it is executed successfully.
The answer to this question could quite possibly be B since once D-H is
completed successfully it protects the session key. Again, can someone
clarify what the Cisco answer would be?
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=28438&t=28438
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
