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Brute Force Attacks. Another approach to determining the WEP key is to use brute force. The shared secret portion of the WEP key is either 40 bits or 104 bits, depending on which key strength you are using. Security researcher Tim Newsham discovered that the key generators from some vendors are flawed. Wireless hex key generator WEP Key Generator. To generate a random WEP key, select the bit key length to generate and press the corresponding button; the ASCII or HEX key can then be copied to your clipboard manually or via the copy to clipboard button to the right of the generated key text field. You can also generate a custom WEP key based on your own pass phrase or other input.
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This chapter is from the book How Secure is Your Wireless Network? Safeguarding Your Wi-Fi LAN
This chapter is from the book
This chapter is from the book
Wep Key Generator
How Secure is Your Wireless Network? Safeguarding Your Wi-Fi LAN
Wep 104 Bit Key Generator For Windows 10
Brute Force Attacks
Another approach to determining the WEP key is to use brute force. The shared secret portion of the WEP key is either 40 bits or 104 bits, depending on which key strength you are using. Security researcher Tim Newsham discovered that the key generators from some vendors are flawed. A brute force attack on a 40-bit key using a weak key generator could take less than a minute to crack.
Key generators enable a user to enter a simple pass phrase to generate the key, instead of entering the key manually with hexadecimal numbers. A 40-bit WEP key shared secret would require 10 hexadecimal numbers; a 104-bit WEP key shared secret would require 26 hexadecimal numbers. As a convenience, some vendors allow you to enter a pass phrase in ASCII that will generate the 10 or 26 hexadecimal numbers for you. The use of a key generator is completely proprietary and not part of any standard. However, note that several different vendors all use the same key generation algorithm.
Tim Newsham discovered that there are a number of problems with the key generators for several vendors. In one example, he noticed that for 40-bit keys, part of the key generation process included a 32-bit seed used in a PRNG. Because the highest bit of each ASCII character is always 0 and the key generator relied on XORing ASCII values, Tim discovered that instead of 00:00:00:00 – ff:ff:ff:ff (32 bits) of possible seeds, only values 00:00:00:00 – 00:7f:7f:7f needed to be considered. This reduced the actual entropy of the PRNG seed to 21 bits. Using a PIII/500 MHz laptop performing 60,000 guesses per second, Newsham was able to crack a 40-bit WEP key from a key generator in 35 seconds.
![104 104](/uploads/1/2/6/0/126043065/497115808.jpg)
The moral of the story: Don't use key generators! Enter your WEP key using manual hexadecimal numbers. When done in this manner, a 40-bit WEP key would have taken 210 days to crack (not a terribly difficult task, when attacked by a Linux cluster).
Alternatively, you can implement 104-bit WEP. Tim noted that the key generator used for 104-bit WEP was not flawed. It was based on an MD-5 hash of the pass phrase. He estimated that a brute force of this key would take 1019 years. Clearly, brute forcing a 104-bit key is a much more difficult task then brute forcing a 40-bit key. When using WEP, always deploy the largest key size available.
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Tags: WEP, encryption, security
Not everything you type as a WEP key is valid, as you might have already noticed. Here are some guidelines to ease creating valid WEP keys manually:
- One ASCII character is 8 bits, one HEX character is 4 bits.
- 64 bit (a.k.a. 40 bit) WEP code has 5 ASCII or 10 HEX characters.
- 128 bit (a.k.a. 104 bit) WEP code has 13 ASCII or 26 HEX characters.
...
In other words: 5/13/16/29 characters are needed for 64/128/152/256-bit WEP
Note: WEP encryption uses 24 bit 'Initilization Vector' in addition to the 'secret key' ( 40 bit for 64 bit WEP, 104 bit for 128 bit WEP, etc.). Therefore, 64 bit WEP can be refered to by some vendors as 40 bit WEP, and 128 bit can be referedo to as 104 bit, depending on the interpretation.
- One ASCII character is 8 bits, one HEX character is 4 bits.
- 64 bit (a.k.a. 40 bit) WEP code has 5 ASCII or 10 HEX characters.
- 128 bit (a.k.a. 104 bit) WEP code has 13 ASCII or 26 HEX characters.
...
In other words: 5/13/16/29 characters are needed for 64/128/152/256-bit WEP
Note: WEP encryption uses 24 bit 'Initilization Vector' in addition to the 'secret key' ( 40 bit for 64 bit WEP, 104 bit for 128 bit WEP, etc.). Therefore, 64 bit WEP can be refered to by some vendors as 40 bit WEP, and 128 bit can be referedo to as 104 bit, depending on the interpretation.
![Wep Wep](/uploads/1/2/6/0/126043065/543924437.png)
Wep 104 Bit Key Generator Download
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