I don't know what the secure phone does, but something like the IMSI Catcher Catcher [1] comes to mind. [1] http://www.sba-research.org/wp-content/uploads/publ

I don't know what the secure phone does, but something like the IMSI Catcher Catcher [1] comes to mind. [1] http://www.sba-research.org/wp-content/uploads/publications/AdrianDabrowski-IMSI-Catcher-Catcher-ACSAC2014-preprint-20140820.pdf http://www.sba-research.org/wp-content/uploads/publications/...