Wep Use

[pmj]

HI. I HOPE SOMEBODY CAN HELP ME WITH THIS. I DON'T KNOW WHAT IS THE REALLY BENEFIT OF USE MORA THAN 1 WEP ENCRYPTION KEY, IF IS ENOUGH TO HAVE THE TRANSMIT KEY TO GET CONNECTION WITH THE AP. I MEAN, IT'S ONLY TO HAVE A TRANSMIT KEY AND A RECEIPT KEY?

[JoshB]

Kill the CAPS man.

I don't know the technical behind it, but I believe it's for a transmission to be more secure by changing WEP keys continually.

[Cell]

Josh has a point there.

The main reason is to act as a form of automatic key rotation, altough, in practice that rotation is manual.
Imagine that use only one key.... a guy with the correct program will have time to find out your WEP key and crack your encription.

But if you change the key often, it will be harder for him to crack it because the keys are changing... ideally, this rotation would be automatic and fast, but WEP needs it to be done manually.

You just configure 4 keys in your AP and then select which index is to be used. After that, just enter that corresponding password on the client and everything is set.

Anyway, WEP is still very weak as protection.

[jekl2000]

Consider 4 stations connected to an AP. They all have the same keys but have different keys selected, usually by a checkbox.

AP keys: (1,2,3,4
key 1: 123
key 2: 456
key 3: 789
key 4 abc

sta 1: ( uses key 1 to transmit)
key 1: 123 (this key selected in config)
key 2: 456
key 3: 789
key 4 abc

sta 2: (uses key 2 to transmit)
key 1: 123
key 2: 456 (this key selected in config)
key 3: 789
key 4 abc

sta 3: ( uses key 3 to transmit)
key 1: 123
key 2: 456
key 3: 789 (this key selected in config)
key 4 abc

sta 4: (uses key 4 to transmit)
key 1: 123
key 2: 456
key 3: 789
key 4 abc (this key selected in config)

The AP will usually use key 1 to transmit unless it is told to use a different key. The AP will indicate in the frame which key to use for decryption.

When sta 4 wants to transmit he will use key 4 and tell the AP to decrypt using key 4 etc etc with the rest of them

This way you can have 4 devices using different encrytion keys, thus making it a little harder for hackers to get everyones key or it can be use to segregate say 4 different departments. If one key is compromised, all dont have to be changed in all devices.

If you look at winxp wep setup, it has an index number drop down box. You cant enter 4 keys, but if you select and index number 1 - 4 and enter the correct key for that number in the AP it will transmit using that key and the AP will xmit back using that key.

So in a nutshell, you can have 4 pcs at home using 4 unique wep keys.

[das.schnelle]

If someone really needed to hack into your network, 35 mins is all it takes at the max. to crack WEP keys. Poor keys may be cracked even earlier. This is because of some flaw in the RC4 algorithm used by WEP. So, it is advised that if you are working on confidential information and are afraid someone may break into your network, it would be better to change them every 30 mins or so.

[ This is my first post by the way.. So, hello all. I hope to be a regular ]

[spiderbite]

somebody did it in like 200 seconds.....


< http://www.securityfocus.com/infocus/1814 >