How safe are cellular networks?

[kyrax12]

How safe are the connections?

Is it as dangerous as connecting to a public wifi?

 

[Thegonagle]

I don't believe it's anywhere near as insecure. Main reason being that your device doesn't connect to a AP/router of unknown configuration where anyone else could be connected with packet sniffers and such.

As far as the cellular air interface goes, it's pretty difficult and/or expensive for an average person to intercept the signal and be able to make any sense out of it. CDMA and OFDMA signals used in cellular networks are pretty well scrambled, and that transmission is likely mixed up with dozens if not hundreds of other simultaneous cell users.

 

[Demo24]

Just a thought, but wouldn't CDMA in theory be more secure due to the central authentication structure vs gsm with sim cards that one could spoof/copy?

 

[slugg]

CDMA is also spoofable. People illegally spoof CDMA modems for free internet access all the time.

 

[Fox5]

I think cellular connections have encryption and switched connections similar to a wifi network. Although in the case of GSM, the encryption is minimal and easily cracked. (this does not apply to the 3g successors to GSM)

Then besides passive decryption, it's also possible to set up a cellular base station and trick people into connecting to it.
http://www.wired.com/threatlevel/2010/07/intercepting-cell-phone-calls/

That's an article on it being done with GSM, but with the advent of software defined radios and GNU radio, I don't see why it couldn't be done on any of the 3g technologies (HSPA, CDMA) too.

 

[Thegonagle]

Just a thought, but wouldn't CDMA in theory be more secure due to the central authentication structure vs gsm with sim cards that one could spoof/copy?

CDMA is also spoofable. People illegally spoof CDMA modems for free internet access all the time.

Cloning an ESN or SIM card to steal internet access is one thing. Reading user data as it goes over the air is another thing altogether, and as far as I know, it's not easy.

it's also possible to set up a cellular base station and trick people into connecting to it.
http://www.wired.com/threatlevel/2010/07/intercepting-cell-phone-calls/

That's an article on it being done with GSM, but with the advent of software defined radios and GNU radio, I don't see why it couldn't be done on any of the 3g technologies (HSPA, CDMA) too.

Of course it's not impossible, but anyone setting that kind of thing in the corner of the coffee shop will look pretty suspicious. The guy sitting in the corner with a WiFi netbook probably looks pretty normal.

 

[dagamer34]

It's about as safe as the Internet in general, however safe you think that is.

 

[Fox5]

Cloning an ESN or SIM card to steal internet access is one thing. Reading user data as it goes over the air is another thing altogether, and as far as I know, it's not easy.




Of course it's not impossible, but anyone setting that kind of thing in the corner of the coffee shop will look pretty suspicious. The guy sitting in the corner with a WiFi netbook probably looks pretty normal.

You wouldn't need a giant antenna for short range, although the technique he used does rely on being the strongest signal to the device iirc.

On the other hand, with a giant antenna like that, he doesn't even need to be in the same building as you...

 

[cl-scott]

I don't know how much this is either fact or fiction, but allegedly US spy agencies like the FBI have portable cellular antennas. So if they want to do a bit of cellular wiretapping on someone, they set up shop in the general vicinity of the target. The person's phone then latches onto this portable antenna as it provides a much better signal, and they can trap all signals going in and out of that antenna.

 

[wirednuts]

I don't know how much this is either fact or fiction, but allegedly US spy agencies like the FBI have portable cellular antennas. So if they want to do a bit of cellular wiretapping on someone, they set up shop in the general vicinity of the target. The person's phone then latches onto this portable antenna as it provides a much better signal, and they can trap all signals going in and out of that antenna.

makes complete sense. i dont see why they wouldnt have that capability. much easier then getting a subpoena to go through the cellular companies computers anyway...

 

[Mopetar]

Quite safe. The only real entities that could afford the necessary equipment and personnel to do this easily could just ask the phone company for your records or legally have the data recorded at the other end, so unless they're using it for intelligence purposes, they won't bother doing it. It's way more likely for your phone to become compromised and start handing out information it shouldn't be to other parties than it is for them to perform some kind of man-in-the-middle attack on a cellular network.

 

[BrightCandle]

The encryption on phones was unfortunately proved flawed quite a few years ago. Anyone wanting to listen to cellular traffic can do so today with moderate equipment.

You should assume every channel to the internet you have is insecure and that all your phone calls are being listened to by a third party.

 

[bigrash]

I use public wifi all the time. Not worried about safety.

 

[Fox5]

Quite safe. The only real entities that could afford the necessary equipment and personnel to do this easily could just ask the phone company for your records or legally have the data recorded at the other end, so unless they're using it for intelligence purposes, they won't bother doing it. It's way more likely for your phone to become compromised and start handing out information it shouldn't be to other parties than it is for them to perform some kind of man-in-the-middle attack on a cellular network.

It would only be a few hundred dollars worth of equipment. The potential gain versus risk probably isn't worth it for the average cyber criminal though, and it requires a very high level of technical expertise.