CompTIA Security Plus Mock Test Q1045

A security administrator must implement a wireless encryption system to secure mobile devices’ communication. Some users have mobile devices which only support 56-bit encryption. Which of the following wireless encryption methods should be implemented?

A. RC4
C. MD5

Correct Answer: A
Section: Cryptography

RC4 is popular with wireless and WEP/WPA encryption. It is a streaming cipher that works with key sizes between 40 and 2048 bits, and it is used in SSL and TLS.

Incorrect Answers:
B: AES supports key sizes of 128, 192, and 256 bits, with 128 bits being the default.
Advanced Encryption Standard (AES) has replaced DES as the current standard, and it uses the Rijndael algorithm. It was developed by Joan Daemen and Vincent Rijmen. AES is the
current product used by U.S. governmental agencies.
C: The Message Digest Algorithm (MD) creates a hash value and uses a one-way hash. The hash value is used to help maintain integrity. There are several versions of MD; the most
common are MD5, MD4, and MD2. MD4 was used by NTLM (discussed in a moment) to compute the NT Hash. MD5 is the newest version of the algorithm. It produces a 128-bit hash.
D: To strengthen WEP encryption, a Temporal Key Integrity Protocol (TKIP) was employed. This placed a 128-bit wrapper around the WEP encryption with a key that is based on
things such as the MAC address of the destination device and the serial number of the packet.

Dulaney, Emmett and Chuck Eastton, CompTIA Security+ Study Guide, 6th Edition, Sybex, Indianapolis, 2014, pp. 171, 250, 251, 255