Steve
Sun Dec 05 04:27:13 CST 2004
> If using WEP or WPA/TKIP you should use a VPN connection to be secure from
> eves droppers.
Not true. WEP (at 128-bit) or WPA/TKIP (at 296-bit: 128-bit key + 128-bit
initialization vector + 40-bit MAC address) are sufficient to protect
against eavesdropping.
With plain WEP, though, if an attacker obtains enough data (about 3
gigabytes) it's possible to determine the key using certain statisical
analysis tools. That's why 802.1X + EAP is better, because it generates new
keys every 60 minutes. WPA/TKIP is improved over this because it generates
new keys every *frame*. But this can create performance drags, so I prefer
WPA/AES instead -- AES is much faster than the RC4 algorithm used in TKIP.
Steve Riley
steriley@microsoft.com
"Niklas" <niklaso@hotmail.com> wrote in message
news:u9mxwCMyEHA.2192@TK2MSFTNGP14.phx.gbl...
>
> WPA (Wi-Fi protected access) is a subset of the 802.11i standard.
> When using wep, the key material used to encrypt/decrypt the data is
> static (you can obtain it dynamically via a radius server)
> with WPA using a pre shared key, you as the client will prove to the
> authenticator that you know the password (and he to you) when that is
> done, you will receive the key material from the authenticator.
> This means that the same plainttext will be different in two different
> sessions.
> When using WPA, if you can, use AES (TKIP uses RC4 for
> encryption/decryption - the same as WEP)
> If using WEP or WPA/TKIP you should use a VPN connection to be secure from
> eves droppers.
> But that might not always be that easy, when using WPA the pre shared key
> can be between 8 and 63 characters, it should always use at least 20 (and
> preferably something that isn't that easy to figure out in a dictionary
> lookup).
>
> Most network adapters and access points can be updated via firmware to
> support WPA (most new adapters already have this capability)
>
> regards
> /Niklas
>
> "Ashish Nair :-)" <Ashish Nair :-)@discussions.microsoft.com> wrote in
> message news:993CEBC9-5428-46F9-BE34-703E697581F1@microsoft.com...
>> Hi All,
>>
>> I would like to discuss this with all of you. What exactly is WPA and
>> How
>> it is different from WEP. Do we need something extra for the products
>> which
>> are accessed usig WEP, and if it had to implement WPA. How can we do
>> that?
>>
>> For eg: Wireless projector has WEP standards in build however what has
>> to
>> be added if we would like to implement WPA instead.
>>
>> Thanx for your co-operation in advance.
>>
>> Regards,
>> Ashish Nair
>
>