Exam 200-355 topic 1 question 205 discussion

Actual exam question from Cisco's 200-355

Question #: 205
Topic #: 1

[All 200-355 Questions]

Which key is established using the four-way handshake during the WPA authentication process?

A. Pairwise Master Key
B. Pairwise Multiple Key
C. Pairwise Session Key
D. Pairwise Transient Key
E. Pairwise Transverse Key

Show Suggested Answer

Suggested Answer: D 🗳️
The authentication process leaves two considerations: the access point (AP) still needs to authenticate itself to the client station (STA), and keys to encrypt the traffic need to be derived. The earlier EAP exchange or WPA2-PSK configuration has provided the shared secret key PMK (Pairwise Master Key). To derive the
PMK from the WPA-PSK, the PSK is put through PBKDF2-SHA1 as the cryptographic hash function. This key is, however, designed to last the entire session and should be exposed as little as possible. Therefore the four-way handshake is used to establish another key called the PTK (Pairwise Transient Key). The PTK is generated by concatenating the following attributes: PMK, AP nonce (ANonce), STA nonce (SNonce), AP MAC address, and STA MAC address. The product is then put through a pseudo random function. http://en.wikipedia.org/wiki/IEEE_802.11i-2004

by Romail at Jan. 17, 2019, 3:05 p.m.

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enpuna

5 years, 10 months ago

Fully agree with Romail link, Here is the clue to answer this triky question: "...A four-way handshake is used to establish another key called the Pairwise Transient Key (PTK)..."

upvoted 1 times

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Romail

6 years, 5 months ago

https://en.wikipedia.org/wiki/IEEE_802.11i-2004

upvoted 2 times

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