Which of the following is used by Wi-Fi Protected Access (WPA) to provide data encryption?
A.
RSA
B.
TKIP
C.
RC4
D.
IDEA
Explanation:
TKIP (Temporal Key Integrity Protocol) is an encryption protocol defined in the IEEE 802.11i standard
for wireless LANs (WLANs). It is designed
to provide more secure encryption than the disreputably weak Wired Equivalent Privacy (WEP). TKIP
is the encryption method used in Wi-Fi
Protected Access (WPA), which replaced WEP in WLAN products.
TKIP is a suite of algorithms to replace WEP without requiring the replacement of legacy WLAN
equipment. TKIP uses the original WEP
programming but wraps additional code at the beginning and end to encapsulate and modify it. Like
WEP, TKIP uses the RC4 streamencryption algorithm as its basis.
What is WPA? Hide
Wi-fi Protected Access (WPA) is an interoperable security standard for Wireless LAN (WLAN). For
using WPA, encryption is
required. WPA provides encryption by using Temporal Key Integrity Protocol (TKIP). TKIP uses a new
encryption algorithm,
which is stronger than WEP algorithm. 802.1x authentication is required in WPA.
Answer option C is incorrect. 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
keystream is not discarded, nonrandom or related
keys are used, or a single keystream is used twice. Some ways of using RC4 can lead to very insecure
cryptosystems such as WEP.
Answer option A is incorrect. The RSA algorithm is an example of the public key algorithm in which
the public key is generated from the private
key. In the RSA algorithm, public and private keys are generated as follows:
1.Choose two large prime numbers p and q of equal lengths, and compute n=p*q.
2.Choose a random public key e such that e and (p-1)*(q-1) are relatively prime.
3.Calculate e*d=1*mod[(p-1)*(q-1)]. Here, d is a private key.
4.Calculate d=e^(-1)*mod[(p-1)*(q-1)].
5.Now (e,n) and (d,n) are the public and private keys respectively.
Answer option D is incorrect. International Data Encryption Algorithm (IDEA) is a block cipher. IDEA
operates on 64-bit blocks using a 128-bit
key. This algorithm was intended as a replacement for the Data Encryption Standard. IDEA was used
in Pretty Good Privacy (PGP) v2.0, and
was incorporated after the original cipher used in v1.0 was found to be insecure. It is an optional
algorithm in OpenPGP. The cipher is
patented in a number of countries but is freely available for non-commercial use. IDEA is a minor
revision of an earlier cipher, PES (Proposed
Encryption Standard). It was originally known as IPES (Improved PES).
Reference:
“http://www.microsoft.com/windowsxp/using/networking/expert/bowman_03july28.mspx”