Security How to keep your wi-fi network secure

allroad

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#1
Protection on wi-fi networks can now be cracked quicker
With growing numbers using wi-fi in their homes, Paul Rubens looks at how good security is on these networks.
In less than two minutes hackers can defeat the security measures protecting many home wireless internet connections.

Defeating these measures could let them capture passwords, steal confidential information or download illegal pornographic material using the connection.

Many home internet users rely on an encryption system called Wireless Equivalent Protection (WEP) to stop others using their wi-fi link, even though WEP has long been known to be flawed.

In early April three cryptographic researchers at the Darmstadt Technical University in Germany revealed a method of exploiting the flaws far more effectively.

Before now it took at least 20 minutes of monitoring the airwaves before it was possible to break in to a wireless network protected by WEP.

Now, armed with a program iwritten by the researchers, it is possible to break in to the same network far faster.

"Breaking in to a WEP protected network is now very easy to do," said Erik Tews, one of the researchers.

"Doing it in 60 seconds is realistic, or five minutes in the very worst case. We think now that WEP is really dead and we recommend that no-one should use it."

In its place he recommends an encryption system called Wi-fi Protected Access (WPA), introduced four years ago to replace WEP. "We have had a very close look at WPA and we can't find anything to exploit," he said.

The only known way to defeat WPA encryption - and WPA2, a newer version - is to use what is known as a brute force dictionary attack.

This involves trying millions of different words or combinations of words from in the hope of stumbling upon the correct password.



There are good reasons for ensuring a home internet connection is as secure as possible, said Struan Robertson, a technology lawyer at legal firm Pinsent Masons.


If your wi-fi is hijacked the police may pay you a visit
"Although home internet users are not responsible for illegal activities carried out by hackers hijacking their internet connection, they do risk having their computer equipment seized by the police," he said.

"If your internet connection is used by a hacker to download illegal pornography, the problem is that the police are likely to come knocking on your door.

"There's a good chance that you will lose your computer while they take it away for forensic analysis and you will then have to go through the painful process of clearing your name with the police who are investigating," he said.

And the consequences could be far more serious for anyone using their home internet connection for business purposes, said Simon Halberstam, head of e-commerce law at Sprecher Grier Halberstam.

WEP is broken


"If you fail to take appropriate technical measures to protect personal data by using a flawed encryption system like WEP you could be breaking the Data Protection Act, and face a fine or even imprisonment," he said.

Yet net providers like BT - one of Britain's largest - continue to put customers at risk by supplying wireless routers pre-configured to use WEP rather than WPA.

"The reason we have gone with WEP is that it will work straight out of the box. Not all laptops or other wireless devices can or do use WPA," said a BT spokesperson.

"There is a small risk from a determined and skilled hacker, but it requires considerable skill and knowledge to break WEP. It is extremely unlikely that you would encounter such a hacker."

Tool time

This may have been true five years ago but cracking a WEP-protected network is now trivial with easy-to-use tools available on the internet.

There are software suites which enable script kiddies - unskilled wannabe hackers - to break in to neighbours' networks without leaving their bedrooms.

The majority of routers are sold without any encryption pre-configured at all, and although buyers can activate WPA encryption themselves, many do not.


Long passwords can thwart dictionary attacks
"There is a lot of fear about switching on encryption," said Rob Falconer, sales and marketing manager at router manufacturer Belkin, which supplies its wireless devices without encryption.

"But we always recommend using WPA or WEP as a bare minimum and we try to make it as easy as possible."

Although customer security is important, financial considerations come first, he said.

"If we shipped them with WPA encryption turned on and unique passwords, our costs would go up dramatically. At the moment we can't see a cost-effective way of doing that."

So what is the best way to protect a home wireless network?

Amit Sinha, a wireless security expert at security consultants AirDefense, dismisses many of the security features - such as MAC address filtering and hiding the name of a home wireless network -offered by wireless routers, because these can be circumvented in seconds by anyone using tools such as Aircrack-ng.

He says home users should always change the password on their router, but concludes that effective encryption is the best solution.

"WEP is broken, so I recommend turning on WPA with a non-dictionary password," he said.

"If you use one which is long enough - at least 20 characters - then it becomes unfeasible for a hacker to mount a brute force attack, because finding your password would take longer than the entire history of the universe," said Mr Sinha
 
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elkopite

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#3
re wi-fi

thanks for that very useful bit of info allroad.....it really does make you think...i've heard of someone being hacked via their nintendo wii wi-fi connection......is nothing sacred???
 

ctexjr

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#4
Great post.
Thank you very much.
After reading this I run to check my Wi Fi connection.
 

earwig999

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#5
My router won't allow a password to be set on my Mac so mine is open. Will this give them access to my Mac or just the Wii as that is the only thing on Wi-Fi
 

notanotherone

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#6
time and time again we see this happening ,i had my mates laptop and was checking it for him and needed to connect to the internet i took upstairs and i was doing a scan to see if it would pick up my router and it picked up 4 open connections in my area 1 ones close to me but dont know who ive been asking around my neighbours to see if i can track them and tell them they have an open connection now if i was dishonest id be on there like shot
 

showders

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#7
I have to admit, i only recently bothered putting passwords on my wi-fi. I was off the opinion "who would do anything bad on mine" but better to be safe than sorry i guess!
 

jkad2000

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#8
Nice post, a while back someone got onto my wifi, added a "readme now" file on my desktop...


luckily he was a "friendly hijacker" & left full instruction on how I should secure my network using NAT, WEP & encryption. He may have scanned my system & not found anything of value as it was a fresh install. how he bypassed winxp firewall is still worrying though!
 

dave577

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#10
didnt realise my wifi was open i didnt see need to secure till i read your post thanks im now secure
 

davidh

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#11
i use wep but even if u got the key i use my router will not let u in because u also have to have had ur mac added to the router table
 

beady

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#12
Sorry mate, but MAC filtering will only keep out a cracker as long as it takes him/her to type

ifconfig <ifname> hw ether <valid MAC address>

If a person is able to crack the key (and it's very easy nowadays with a bit of technical knowhow, and is discussed in lots of places, including this great forum ), MAC filtering is next to useless. The same goes for disabling the BSSID broadcast. It adds virtually nothing to the actual security, and probably makes it worse, since you think you're protected when you're not.
You need a VERY good reason not to use WPA with a good, long, non-dictionary based password.

All this also applies to Windows, there are plenty of programs around to change a wireless cards MAC. See e.g. http://www.klcconsulting.net/Change_MAC_w2k.htm ).

Hope this helps
 

totalgenius

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#13
Sorry mate, but MAC filtering will only keep out a cracker as long as it takes him/her to type

ifconfig <ifname> hw ether <valid MAC address>

If a person is able to crack the key (and it's very easy nowadays with a bit of technical knowhow, and is discussed in lots of places, including this great forum ), MAC filtering is next to useless. The same goes for disabling the BSSID broadcast. It adds virtually nothing to the actual security, and probably makes it worse, since you think you're protected when you're not.
You need a VERY good reason not to use WPA with a good, long, non-dictionary based password.

All this also applies to Windows, there are plenty of programs around to change a wireless cards MAC. See e.g. http://www.klcconsulting.net/Change_MAC_w2k.htm ).

Hope this helps
Your are correct matey.

To secure you wifi even furthur ( Can still be hacked in to by experts, no chance for average newbie.)
  1. Hide SSID
  2. Use either WPA or WPA2.
  3. Enable MAC Filtering.
  4. Limit you signal transmit power.
  5. If you use wifi in only certain part of your house then replace the omnidirectional router antenna with a directional antenna.
Hope this helps.
 
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beady

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#14
I see what you're saying, but I would argue that if you use WPA with a good password, then there's no reason to have MAC filtering. Same goes for disabling BSSID broadcasts. Infact, the hassles that go with MAC filtering and no broadcast (difficulty connecting with some clients,having to set everything up manually and logging into the router each time you want to add a device etc) mean I think these 'security features' shouldn't be used.

The security of WPA comes from the password. Anything else isn't required, and just adds problems. And even if WPA turns out to be crackable sometime in the future, hiding your MAC will do naff all to help.

Still, this is just my opinion. :)
 

T4i

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I see what you're saying, but I would argue that if you use WPA with a good password, then there's no reason to have MAC filtering. Same goes for disabling BSSID broadcasts. Infact, the hassles that go with MAC filtering and no broadcast (difficulty connecting with some clients,having to set everything up manually and logging into the router each time you want to add a device etc) mean I think these 'security features' shouldn't be used.

The security of WPA comes from the password. Anything else isn't required, and just adds problems. And even if WPA turns out to be crackable sometime in the future, hiding your MAC will do naff all to help.

Still, this is just my opinion. :)
Yep, pretty good explanation. WPA can only be hacked by dictionary bruteforce? So if you use a good enough password your pretty much fine. My password is a combination of letters/numbers and other characters. So basically its not even in the dictionary.

I use WPA2 with AES, MAC filtering, no DHCP.

I can see about 4 networks, 1 one which is completely open (wtha 10mb cable connection) and 3 others are WEP.
 
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#16
ive recently stumbled upon a little program called ipig. can anyone explain the benefits of using this security tool on my wifi connection. i dont fully understand it but it connects to a named server which then blocks attack from outside the wlan connection. "I think thats how it works anyhow" lol also can anyone answer me if i have to keep dhcp set to on because my router conects to my modem which sets a dynamic ip?
 
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beady

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#17
Hi Wenglish,
I've had a quick look at ipig, and it looks like a program that sets up an encrypted connection to a proxy server, It doesn't really have anything to do with wireless security per se, it encrypts all your communications. I'm guessing it works like this:

-You want to check your emails at home.
-Ipig on your computer connects to the ipig server and sets up an encrypted communication channel
-Your email client then sends data through the encrypted channel to the ipig server, which then decrypts it and sends it on the the email server.
-Anything back from the email server goes to the ipig server, where it is encrypted and sent back to your computer.

It really depends how paranoid you are as to whether you want to use this. Potential problems are:
1. Why should you trust the ipig server? It can decrypt everything you send or receive.
2. Assuming you do trust the ipig server, the data is only encrypted between you->server, not server->email server. It's possible to intercept the data anywhere along the unencrypted link. Only really adds protection against someone sniffing your wireless or cable connection at a fairly local level ( e.g. same street ).
3. Likely to slow your internet speed down.

If you've already got WPA on your router (and you should have), I wouldn't bother with this. Even if it works as it's intended, it only gives a little added protection. Websites like ebay and hotmail etc. already use encryption that is tried and tested, so ipig adds nothing in this case.

Ipig might protect your day to day browsing a little, but I don't really think it's worth the hassle. If you are genuinely worried about your data, there are probably better products available (unfortunately I can't think of any general ones off hand. )

In summary, I'd avoid ipig. But maybe thats because I don't know enough about it. My gut says steer clear though.

edit: I've had a VERY cursory look at the protocol, and it seems to be reasonably secure. It basically relies on the strength of the password (which the user chooses, so make it a good one). There doesn't seem to be any authentication of the server to the client, but since only the real server knows your password, this negates simple 'man in the middle' attacks. I don't think it'd be useful on your home network (with WPA!!), but it should make surfing at public hotspots more secure.

Hope this helps
 
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toofaz

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#18
I've been using WEP since I first went wireless, I knew it wasn't perfect but didn't realise how easy it was to crack. Cheers for the info, WPA all the way now
 

conorc

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#20
Use WPA (or, even better, WPA2)
A long (>20 characters) passphrase/password with numbers and symbols in it

Forget hideing SSID
Forget MAC filtering
Forget WEP

The only add a FALSE sense of security.

If your equipment doesn't handle WPA, upgrade!

You are not secure if you don't use WPA/WPA2!!!!!!
 
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