NetStumbler.org Forums - View Single Post

JimmyPopAli · 07-26-2002

Q: Different equipment is marked as 40-bit, 64-bit, 104-bit and 128-bit WEP. Where can I learn more about WEP?

A: Actually, there are only two classes of WEP. However, due to the manner in which it is expressed, each class may be called by one of two different names. What you need to remember:

40-bit WEP is the same as 64-bit WEP.
104-bit WEP is the same as 128-bit WEP.

This is because the initialization vector used in the encryption is 24 bits. Therefore, 40+24=64, and 104+24=128. They are the same classes, just a different way to express it.

One other detail to note: Only 40/64-bit WEP is defined in the 802.11b standard. 104/128-bit WEP is implemented by many manufacturers, but it is not part of the standard. This means that different brands of equipment may not communicate with other brands using 104/128-bit WEP. While some do communicated well (e.g. Linksys and ORiNOCO), many units will work only at the 40/64-bit level with other brands of equipment .

============================================

Q: Where can I learn more about WEP?

A: Here are some good sites loaded with information on WEP.

Weaknesses in the Key Scheduling Algorithm of RC4
http://online.securityfocus.com/data...c4_ksaproc.pdf

Attack to Break WEP
http://www.cs.rice.edu/~astubble/wep/

Cracking WEP Keys. Presented at Blackhat 2001
http://www.lava.net/~newsham/wlan/WE...rd_cracker.ppt

Practical Exploitation of RC4 Weaknesses in WEP Environments
http://dachb0den.com/projects/bsd-airtools/wepexp.txt

802.11b Wireless Security
http://www.dachb0den.com/projects/bs...s/wireless.ppt

07-26-2002	#3 (permalink)
JimmyPopAli Registered Member Join Date: Apr 2002 Location: Washington the state Posts: 242	WEP information Q: Different equipment is marked as 40-bit, 64-bit, 104-bit and 128-bit WEP. Where can I learn more about WEP? A: Actually, there are only two classes of WEP. However, due to the manner in which it is expressed, each class may be called by one of two different names. What you need to remember: 40-bit WEP is the same as 64-bit WEP. 104-bit WEP is the same as 128-bit WEP. This is because the initialization vector used in the encryption is 24 bits. Therefore, 40+24=64, and 104+24=128. They are the same classes, just a different way to express it. One other detail to note: Only 40/64-bit WEP is defined in the 802.11b standard. 104/128-bit WEP is implemented by many manufacturers, but it is not part of the standard. This means that different brands of equipment may not communicate with other brands using 104/128-bit WEP. While some do communicated well (e.g. Linksys and ORiNOCO), many units will work only at the 40/64-bit level with other brands of equipment . ============================================ Q: Where can I learn more about WEP? A: Here are some good sites loaded with information on WEP. Weaknesses in the Key Scheduling Algorithm of RC4 http://online.securityfocus.com/data...c4_ksaproc.pdf Attack to Break WEP http://www.cs.rice.edu/~astubble/wep/ Cracking WEP Keys. Presented at Blackhat 2001 http://www.lava.net/~newsham/wlan/WE...rd_cracker.ppt Practical Exploitation of RC4 Weaknesses in WEP Environments http://dachb0den.com/projects/bsd-airtools/wepexp.txt 802.11b Wireless Security http://www.dachb0den.com/projects/bs...s/wireless.ppt Last edited by Thorn : 03-17-2003 at 07:08 AM.