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I'm very noob to this kind of networks. My question is how to get a phone (without a sim card -as far as I can tell-) to authenticate to your new BTS ?

by Raed667 11y ago

tbrock 11y ago
The phones have SIM cards (subscriber identification modules). However, they are not authenticated by this network to see if they are paying customers or whatever because this is an experiment.
waitingkuo 11y ago
You need a GSM Core Network[1]. For more details, you can take a look at HLR and AuC components which are responsible for authentication. [1] https://en.wikipedia.org/wiki/Network_switching_subsystem#Authentication_center_.28AuC.29 https://en.wikipedia.org/wiki/Network_switching_subsystem#Au...
cnvogel 11y ago
The network could blindly accept any phone, and distinguish by IMEI (phone identification) instead of IMSI (subscriber identification), I think. But as the former doesn't have any cryptographical authentication, it's trivially easy to spoof a different identity. To have "proper" user authentication, you could just buy blank SIM cards which you can provision with keys and identification as you see fit. http://www.aliexpress.com/item/SIM-USIM-Card-4G-LTE-Blank-Mini-Nano-micro-SIM-Card-For-Telecommunications-Operator/32272750097.html http://www.aliexpress.com/item/SIM-USIM-Card-4G-LTE-Blank-Mi...
extrapickles 11y ago
Basically if the phone cannot find a BTS for its normal carrier, it will ask the other BTS that it can find if it can connect. There normally isn't any authentication done to see if the BTS is legit. This is also what the police stingray devices take advantage of.
lb1lf 11y ago
Basically (as has been pointed out below), authentication is more of an issue in the opposite direction - when the GSM spec was hammered out, carriers were concerned with rogue handsets, not that someone, somewhere would set up a rogue network (as the package in the article pretty much is, at least from the perspective of the established carriers.) In NMT networks, for instance, ghost handsets were a major issue - you could register onto the network and place calls and the operator would have nowhere to send the bill. Not such a good idea for ordering pizza, but great for lengthy international calls. Here in Norway I seem to recall that our national telco simply blocked calls from the NMT cellular network to a number of countries on the assumption that any call placed would be fraudulent, anyway.

I'm very noob to this kind of networks. My question is how to get a phone (without a sim card -as far as I can tell-) to authenticate to your new BTS ?

by Raed667 11y ago

I'm very noob to this kind of networks. My question is how to get a phone (without a sim card -as far as I can tell-) to authenticate to your new BTS ?

tbrock 11y ago

The phones have SIM cards (subscriber identification modules). However, they are not authenticated by this network to see if they are paying customers or whatever because this is an experiment.

waitingkuo 11y ago

You need a GSM Core Network[1]. For more details, you can take a look at HLR and AuC components which are responsible for authentication. [1] https://en.wikipedia.org/wiki/Network_switching_subsystem#Authentication_center_.28AuC.29 https://en.wikipedia.org/wiki/Network_switching_subsystem#Au...

cnvogel 11y ago

The network could blindly accept any phone, and distinguish by IMEI (phone identification) instead of IMSI (subscriber identification), I think. But as the former doesn't have any cryptographical authentication, it's trivially easy to spoof a different identity. To have "proper" user authentication, you could just buy blank SIM cards which you can provision with keys and identification as you see fit. http://www.aliexpress.com/item/SIM-USIM-Card-4G-LTE-Blank-Mini-Nano-micro-SIM-Card-For-Telecommunications-Operator/32272750097.html http://www.aliexpress.com/item/SIM-USIM-Card-4G-LTE-Blank-Mi...

extrapickles 11y ago

Basically if the phone cannot find a BTS for its normal carrier, it will ask the other BTS that it can find if it can connect. There normally isn't any authentication done to see if the BTS is legit. This is also what the police stingray devices take advantage of.

lb1lf 11y ago

Basically (as has been pointed out below), authentication is more of an issue in the opposite direction - when the GSM spec was hammered out, carriers were concerned with rogue handsets, not that someone, somewhere would set up a rogue network (as the package in the article pretty much is, at least from the perspective of the established carriers.) In NMT networks, for instance, ghost handsets were a major issue - you could register onto the network and place calls and the operator would have nowhere to send the bill. Not such a good idea for ordering pizza, but great for lengthy international calls. Here in Norway I seem to recall that our national telco simply blocked calls from the NMT cellular network to a number of countries on the assumption that any call placed would be fraudulent, anyway.