relative security risks for WEP & WPA?

Okay, I typically use WEP in the higher 128-bit mode on my Dlink
routers. The new Dlink router I just upgraded to offers WPA, but my
older Dlink PC-CARD 11b wifi card doesn't have WPA capabilities, so I'm
sticking to 128-bit WEP.

Now, I've been curious, I know that WEP has been cracked, but is that
only referring to the default 64-bit WEP? How secure is 128-bit WEP?
Also my Dlink router and PC-CARD both offer a proprietary 256-bit WEP.
How secure would that be? Is any WEP secure? Can I enable WPA and still
use my WEP-only network card?

Yousuf Khan

On 22 Dec 2004 14:39:06 -0800, "YKhan" <(E-Mail Removed)> wrote:
>Okay, I typically use WEP in the higher 128-bit mode on my Dlink
>routers. The new Dlink router I just upgraded to offers WPA, but my
>older Dlink PC-CARD 11b wifi card doesn't have WPA capabilities, so I'm
>sticking to 128-bit WEP.

I'm in exactly the same boat. My GemTek WL-350 doesn't support WPA.

>Now, I've been curious, I know that WEP has been cracked, but is that
>only referring to the default 64-bit WEP? How secure is 128-bit WEP?
>Also my Dlink router and PC-CARD both offer a proprietary 256-bit WEP.
>How secure would that be? Is any WEP secure?

The short answer is "not particularly." See below.

"Making matters even worse, the cracking techniques most frequently
used will work equally well no matter what WEP key length you're
using. Thus, a 128-bit key is just as vulnerable as a 64-bit key.
Indeed, even if a WEP key was 1,204 bits, it still as crackable by
today's methods as one's that the minimal 64-bits."

http://www.wi-fiplanet.com/tutorials...le.php/2106281

"As a rule of thumb, shoot for a minimum of 200,000 for a 64 bit [WEP]
key and 500,000 for a 128 bit key..."

http://securityfocus.com/infocus/1814

>Can I enable WPA and still use my WEP-only network card?

No, I don't think so. Hence why I'm looking for a new mini PCI for
the laptop.

Wep is wep, the reasons it is crackable at 64 is the same at 128. Keep
in mind that it takes about 10,000,000 packets or more captured to get
a wep key, so if you are a casual user, the chances of someone breaking
in are slim. To my humble knowledge, you ought to be able to run WPA on
certain devices and WEP on others at the same time,, but,, this makes
WPA as insecure as WEP. WPA using rc4 encrytion is supposed to be
backward compatible with wep.

According to one of those articles, the latest techniques let you crack
WEP in 200,000 to 500,000 packets (64- and 128-bit respectively), not
10 million!

Yousuf Khan

On 23 Dec 2004 09:58:41 -0800, "YKhan" <(E-Mail Removed)> wrote:
>According to one of those articles, the latest techniques let you crack
>WEP in 200,000 to 500,000 packets (64- and 128-bit respectively), not
>10 million!

Yes, exactly. From the SecurityFocus article:

"[T]he KoreK attacks [implemented in, for example, aircrack] change
everything. No longer are millions of packets required to crack a WEP
key; no longer does the number of obviously "weak" or "interesting"
IVs matter. With the new attacks, the critical ingredient is the total
number of unique IVs captured, and a key can often be cracked with
hundreds of thousands of packets, rather than millions."

Maybe my specs are out of date but still for a casual user 200,000
packets is quit a bit.
Considering if all packets were maxed at 2346 bytes thats about 46
gigabytes of data.
I dont do anything important enough at home to worry about it. Most
important or critical stuff I do over the web is encrypted using https.
If people want to see what I type in newsgroups then by all means,
crack my wep key and have at it.

Airhead schrieb:
> Maybe my specs are out of date but still for a casual user 200,000
> packets is quit a bit.
> Considering if all packets were maxed at 2346 bytes thats about 46
> gigabytes of data.
> I dont do anything important enough at home to worry about it. Most
> important or critical stuff I do over the web is encrypted using https.
> If people want to see what I type in newsgroups then by all means,
> crack my wep key and have at it.

Strange...

I end up with 200,000 * 2346 byte = 469.2 MegaByte.

In reality, IP packets have an average size of maybe a few hundred byts
(consider all the TCP management packets, login stuff ...).

Probably one shouldn't count MegaBytes, but sth. like TCP
transactions... (or simply packets).


Michael


--
Michael Schmidt
University of Siegen, Germany
http: www.dcs.uni-siegen.de
e-mail: schmidt _at_ nue.et-inf.uni-siegen.de

"Michael Schmidt" <(E-Mail Removed)> wrote in
message news:(E-Mail Removed)...
> Airhead schrieb:
> > Maybe my specs are out of date but still for a casual user 200,000
> > packets is quit a bit.
> > Considering if all packets were maxed at 2346 bytes thats about 46
> > gigabytes of data.
> > I dont do anything important enough at home to worry about it.
Most
> > important or critical stuff I do over the web is encrypted using
https.
> > If people want to see what I type in newsgroups then by all means,
> > crack my wep key and have at it.
>
> Strange...
>
> I end up with 200,000 * 2346 byte = 469.2 MegaByte.

Thanks, my calculator must of had to much wine.

>
> In reality, IP packets have an average size of maybe a few hundred
byts
> (consider all the TCP management packets, login stuff ...).
>
> Probably one shouldn't count MegaBytes, but sth. like TCP
> transactions... (or simply packets).
>
>
> Michael
>
>
> --
> Michael Schmidt
> University of Siegen, Germany
> http: www.dcs.uni-siegen.de
> e-mail: schmidt _at_ nue.et-inf.uni-siegen.de