Which of the following encryption algorithm is used by Wired Equivalent Privacy (WEP)?
A.
RC4
B.
RSA
C.
IDEA
D.
SHA
Explanation:
The RC4 encryption algorithm is used by Wired Equivalent Privacy (WEP).
Wired Equivalent Privacy (WEP) is a security protocol for wireless local area networks (WLANs). It
has two components, authentication and encryption. It provides security, which is equivalent to
wired networks, for wireless networks. WEP encrypts data on a wireless network by using a fixed
secret key. WEP incorporates a checksum in each frame to provide protection against the attacks
that attempt to reveal the key stream.Answer option D is incorrect. The Secure Hash Algorithm (SHA) is a cryptographic hash algorithm. It
generates a fixed-length digital representation (message digest) of an input data sequence of any
length. The SHA algorithm is very secure, as it is computationally very difficult to find a message that
corresponds to a given message digest. In this algorithm, any change to a message will result in a
completely different message digest. There are five SHA algorithms: SHA-1, SHA-224, SHA-256, SHA-
384, and SHA-512.
Answer option B 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 C 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://en.wikipedia.org/wiki/RC4”