JK0-U31 Latest Exam Braindumps
Question 9: You are implementing wireless access at a defense contractor.Specifications say, you must implement the AES Encryption algorithm. Which encryption standard
should you choose?
A. WEP
B. WPA
C. TKIP
D. WPA 2
Correct Answer: D
Explanation:
WPA 2 (Wi Fi Protected Access 2) uses AES encryption, which is endorsed by the National Security
Administration. What is AES? The Advanced Encryption Standard (AES) is an encryption standard
adopted by the U.S. government. The standard comprises three block ciphers, AES-128, AES-192,
and AES-256. Each AES cipher has a 128-bit block size, with key sizes of 128, 192, and 256 bits,
respectively. The AES ciphers have been analyzed extensively and are now used worldwide, as was
the case with its predecessor, the Data Encryption Standard (DES). AES was announced by National
Institute of Standards and Technology (NIST) as U.S. FIPS PUB 197 (FIPS 197) on November 26, 2001
after a 5-year standardization process in which fifteen competing designs were presented and
evaluated before Rijndael was selected as the most suitable. It became effective as a standard on
May 26, 2002. As of 2009, AES is one of the most popular algorithms used in symmetric key
cryptography. It is available in many different encryption packages. AES is the first publicly
accessible and open cipher approved by the NSA for top secret information. Answer optiond A and
B are incorrect. WEP and WPA both use the RC-4 Stream cipher. What is RC4? RC4 is a stream cipher
designed by Ron Rivest.
It is used in many applications, including Transport Layer Security (TLS), Wired Equivalent Privacy
(WEP), Wi-Fi Protected Access (WPA), etc. RC4 is fast and simple. However, it has weaknesses that
argue against its use in new systems. It is especially vulnerable when the beginning of the output
key stream is not discarded, nonrandom or related keys are used, or a single key stream is used
twice. Some ways of using RC4 can lead to very insecure cryptosystems such as WEP . Answer option
C is incorrect. Temporal Key Integrity Protocol is a substitute for WPA, meant to replace WEP
without requiring that hardware be replaced.
Reference: http.//en.wikipedia.org/wiki/IEEE_802.11i
