Wireless Cryptography & Stream Ciphers

Question 1

What is RC4?

Answer 1

A stream cipher that is fast and operates in 1 round.

Key size ranges from 1–256 bytes (8–256 bits).

Question 2

What is the common usage of RC4 in WEP?

Answer 2

WEP uses a 40-bit key combined with a 24-bit IV.

WEP is very insecure and has been deprecated.

Question 3

What is the common usage of RC4 in WPA?

Answer 3

WPA uses a 128-bit key and a 40-bit IV.

WPA is more secure than WEP but still crackable.

Question 4

Who designed RC4?

Answer 4

RC4 was designed by RSA.

Question 5

What are the weaknesses of WEP?

Answer 5

WEP has no replay attack protection, no tamper detection, uses a global key for all users, and is breakable by frequency analysis.

Question 6

What is TKIP?

Answer 6

TKIP stands for Temporal Key Integrity Protocol and fixes WEP flaws by increasing the IV to 48 bits and using session keys.

Question 7

What does WPA stand for?

Answer 7

WPA stands for Wi-Fi Protected Access.

Question 8

What is the difference between WPA and WPA Enterprise?

Answer 8

WPA uses a pre-shared key, while WPA Enterprise uses 802.1X, EAP, and an authentication server for individual logins.

Question 9

What is WPA2?

Answer 9

WPA2 uses AES-CCMP for 128-bit encryption and supports both pre-shared key and enterprise mode.

Question 10

What are the wireless authentication protocols supported by WPA2?

Answer 10

WPA2 supports PEAP, EAP-TLS, and LEAP (now deprecated).

Question 11

What is the modern standard for Wi-Fi security?

Answer 11

WPA2 is considered the modern standard for Wi-Fi security.

Question 12

What type of cipher is ChaCha?

Answer 12

ChaCha = ✅ Stream cipher

Designed as a faster, more secure alternative to RC4

Question 13

What type of cipher is ChaCha NOT?

Answer 13

ChaCha is NOT a block or asymmetric cipher.

Question 14

What key sizes does RC4 use in WEP?

Answer 14

RC4 used in WEP with:
✅ 40-bit key (original)
✅ 128-bit key (improved version)

Still weak due to poor IV management