Setting up WEP security

Ian Stirling wrote:
> Grumps <(E-Mail Removed)> wrote:
>> "Ian Stirling" <(E-Mail Removed)> wrote in message
>> news:45d088ef$0$8745$(E-Mail Removed)...
>>> Mark McIntyre <(E-Mail Removed)> wrote:
>>>> On 12 Feb 2007 03:34:11 GMT, in uk.telecom.broadband , Ian Stirling
>>>> <(E-Mail Removed)> wrote:
>>>>
>>>>> Steven Penn <(E-Mail Removed)> wrote:
>>>>>>
>>>>>> "Ashley" <(E-Mail Removed)> wrote in message
>>>>>> news:(E-Mail Removed)...
>>>>>>>
>>>>>>> Easy is subjective. In the context of wireless security WEP
>>>>>>> *is* easy to
>>>>>>> crack, MAC spoofing is even easier, WPA is much more robust.
>>>>>>
>>>>>> What you are really saying is:
>>>>>> 'its easy if you know how'...
>>>>>
>>>>> All it takes is a bored 12 year old, with the ability to follow
>>>>> simple scripts, and the motivation of not having ADSL.
>>>>> This is not complex or hard to do.
>>>>
>>>> Wel,, its not *quite* that easy, though it isn't that hard either.
>>>> You'll need a laptop with a supported wireless card, prolly a linux
>>>> distro on it, and the right tools. A bored 12-year old /could/ get
>>>> hold of these, but probably not without a net connection of their
>>>> own. They'd also have to be close enough to your network to capture
>>>> traffic, and you'd have to generate enough for them to capture.
>>>
>>> No ADSL does not mean no dialup.
>>> This, and a linux CD/DVD is pretty much all you need.
>>>
>>> Put it this way - I'm fairly sure that at 12, I would have been
>>> doing this, if I had no fast net connection, and also showing
>>> others how to do it.
>>
>> Would you? Even knowing that it's a criminal offense, and people
>> have been prosecuted for it?
>
> I was 12, morals were not really very well developed.
>
>> Hi tech joy riding! The only difference between stealing a car and
>> someone's bandwidth is that the car thief gets a slap on the wrist,
>> whereas the bandwidth stealer goes to jail with a ?500 fine.
>
> Umm. No.
> The number of people who have actually be convicted for bandwidth
> stealing is in low single figures IIRC.

I guess the guy that turns up when you google the offence, must've been a
real hard case to have had such a hefty verdict.

Steven Penn wrote:

> What you are really saying is:
>
> 'its easy if you know how'...

Perhaps, using a PC is easy if you know how, driving is easy if you know
how.

> So is brain surgery I suppose.
>
> But how many brain surgeons live up your street?

How many drivers live up your street?

Like I said its subjective, in the context of wireless security WEP
provides exactly what it stands for - not much.

On 12 Feb 2007 15:34:07 GMT, in uk.telecom.broadband , Ian Stirling
<(E-Mail Removed)> wrote:

>No ADSL does not mean no dialup.
>This, and a linux CD/DVD is pretty much all you need.

Downloading a linux CD/DVD over /dialup/ ?
>For very minimal outlay, just a bit of scrounging, you can work wi-fi routers
>at ranges of a kilometer, with no equipment other than a standard USB
>key.

You can hear them, possibly, but you need to amplify both ends.
--
Mark McIntyre

"David G. Bell" <(E-Mail Removed)> wrote:
> On Thursday, in article
> <(E-Mail Removed)>
> (E-Mail Removed)lid "NoNeedToKnow" wrote:

> > I suspect you mean 26 hex numerals, or 13 characters...

> I checked on my hardware, and, yes, that is what it requires.

> Which seems odd, at 8 bits per character, and requiring printable
> characters.

"128-bit WEP" uses 104 bits of shared key, and 24 bits of "initialisation
vector". The IV is prepended to the key to create the 128-bit seed used
by the encryption algorithm, and is (usually) different for every
packet. 104 bits is 13 bytes, which could be expressed as 26 hex digits.

Beware systems that use 13 *characters* -- for a start, that usually
means you typically only use printable ASCII characters in the range
33-126 so you have the equivalent of only about 80-odd bits of
randomness. Moreover, there's no official standard way of generating the
key from those characters, and so no guarantee that two devices will
create the same key from your 13-character passphrase. Stick to 26 hex
digits.

But as others have noted, WEP is not very secure anyway.

--
Pete Peter Turnbull
Network Manager
University of York

Mark McIntyre <(E-Mail Removed)> wrote:
> On 12 Feb 2007 15:34:07 GMT, in uk.telecom.broadband , Ian Stirling
> <(E-Mail Removed)> wrote:
>
>>No ADSL does not mean no dialup.
>>This, and a linux CD/DVD is pretty much all you need.
>
> Downloading a linux CD/DVD over /dialup/ ?
>>For very minimal outlay, just a bit of scrounging, you can work wi-fi routers
>>at ranges of a kilometer, with no equipment other than a standard USB
>>key.
>
> You can hear them, possibly, but you need to amplify both ends.

No, you don't.
That's what the dish is for.
The dish automatically amplifies both sides.

If an omni antenna would work to 50m, then you need an antenna with
(1Km/50m)^2 more directivity, or 400 times.
Or alternatively, around .1 radians, or 6 degrees.
At 2.4Ghz, this needs a dish of around:
0.1 radians = 1.22* .125m / d
=>
0.1 d = 1.22 * .125m
=>
d = 10 * 1.22 *.125m
=>
d = 1.5m

Ok - a kilometer was optimistic with a wok - .5Km is possible though.