C839v5 / D334 Chapter 12 – Wireless Security Knowledge Check (WEP, WPA, TKIP, RC4)|Verified A+ Graded Rationales Latest Updated 2026

C839v5 / D334 Chapter 12 – Wireless Security Knowledge Check (WEP, WPA, TKIP, RC4)|Verified A+ Graded Rationales Latest Updated 2026 From the list below, select the options that underscore weaknesses in WEP. Select all that apply. - Small value of IV - No IV used - Lack of message tampering identification - No master key used - Small value of IV - Lack of message tampering identification Explanation: WEP is weak from a number of viewpoints including: • Small value of IV. This meant that it repeated within a reasonable time, and the key could then be attacked. • Construction of keys made it susceptible to the weak key attacks (FMS attack). • Lack of protection against message replay. There was no protection against cipher streams being played back over the network. • Lack of message tampering identification. The method did not support the detection of message tampering. • Directly used a master key. The method had no way of updating the keys. The initialization vector used with WEP is _____ bits long? 24 Explanation: Within IEEE 802.11 networks, WEP (Wired Equivalent Protocol), which uses RC4 and a 24-bit IV, could roll-around after a few hours. This method was replaced by TKIP (Temporal Key Integrity Protocol) and which had a 48-bit IV value, and where a session key was used as the seed for the S-box. Select the the weaknesses in WEP from the list below. Select all that apply. - Small value of IV - Susceptibility to Fluhrer, Mantin, Shamir attack - Lack of message tampering identification - Susceptibility to message replay - Small value of IV - Susceptibility to Fluhrer, Mantin, Shamir attack - Lack of message tampering identification - Susceptibility to message replay Explanation: WEP is weak from a number of viewpoints including: • Small value of IV. This meant that it repeated within a reasonable time, and the key could then be attacked. • Construction of keys made it susceptible to the weak key attacks (FMS attack). • Lack of protection against message replay. There was no protection against cipher streams being played back over the network. • Lack of message tampering identification. The method did not support the detection of message tampering. • Directly used a master key. The method had no way of updating the keys. WEP uses the block cipher RC4 configured for operation with 40-bit keys. True or False False Explanation: WEP uses the RC4 stream cipher. With this we have a 24-bit IV and a 40-bit key. WPA uses RC4 with TKIP (Temporal Key Integrity Protocol) for encryption and has a ____-bit IV value. 48 24 40 128 48 Explanation: Within IEEE 802.11 networks, WEP (Wired Equivalent Protocol), uses RC4 and a 24-bit IV, which could roll-around after a few hours. This method was replaced by TKIP (Temporal Key Integrity Protocol) and which had a 48-bit IV value, and where a session key was used as the seed for the S-box. WPA uses RC4 with TKIP (Temporal Key Integrity Protocol) for encryption at ____bits. 48 24 40 128 128 Explanation: Within IEEE 802.11, wi-fi has evolved through the usage of the RC4 stream encryption method. Because of export restrictions, the size of the original key in RC4 was limited to 40 bits (for WEP) and was then increased to 128 bits (TKIP). Wi-Fi Protected Access (WPA) uses ____-bit RC4 with TKIP for encryption.