Some dangers from 2G networks legacy support and a possible mitigation

We present in this short study, some of the well-known problems with the current legacy support for 2G cellular networks, and the security and authentication problems this poses, as demonstrated in recent document leaks about spying from US embassies [1]. We have conducted focused radio measurements in the Helsinki Metropolitan area on these security problems and present some of the findings here. Also, we propose some mitigation methods for the most likely scenarios that arise in supporting legacy 2G systems in modern operator networks.