\select@language {english} \contentsline {chapter}{\numberline {1}Introduction}{1} \contentsline {section}{\numberline {1.1}Motivation}{1} \contentsline {section}{\numberline {1.2}Structure}{2} \contentsline {section}{\numberline {1.3}Disclaimer}{2} \contentsline {section}{\numberline {1.4}On Typesetting}{3} \contentsline {chapter}{\numberline {2}GSM}{5} \contentsline {section}{\numberline {2.1}A Historical Perspective}{5} \contentsline {section}{\numberline {2.2}The GSM Network}{7} \contentsline {subsection}{\numberline {2.2.1}Mobile Station}{9} \contentsline {subsection}{\numberline {2.2.2}Network Subsystem}{11} \contentsline {subsubsection}{Mobile Switching Center}{12} \contentsline {subsubsection}{Home Location Register}{12} \contentsline {subsubsection}{Visitor Location Register}{14} \contentsline {subsubsection}{Authentication Center}{14} \contentsline {subsection}{\numberline {2.2.3}Base Station Subsystem}{16} \contentsline {subsubsection}{Frequencies and the Cellular Principle}{16} \contentsline {subsubsection}{Base Transceiver Station}{18} \contentsline {subsubsection}{Base Station Controller}{19} \contentsline {section}{\numberline {2.3}The $U_m$ Interface}{21} \contentsline {subsection}{\numberline {2.3.1}Radio Transmission}{21} \contentsline {subsubsection}{Frame Numbering}{22} \contentsline {subsubsection}{Burst Types}{24} \contentsline {subsection}{\numberline {2.3.2}Logical Channels}{25} \contentsline {subsubsection}{Dedicated Channels}{25} \contentsline {subsubsection}{Common Channels}{26} \contentsline {subsubsection}{Combinations}{27} \contentsline {subsection}{\numberline {2.3.3}Layers}{27} \contentsline {paragraph}{Physical Layer (Layer 1):}{27} \contentsline {paragraph}{Data Link (Layer 2):}{28} \contentsline {paragraph}{Network (Layer 3):}{28} \contentsline {section}{\numberline {2.4}IMSI-Catcher}{28} \contentsline {subsection}{\numberline {2.4.1}Mode of Operation}{29} \contentsline {subsubsection}{Attacks}{31} \contentsline {paragraph}{MS is in normal cell selection mode:}{31} \contentsline {paragraph}{MS is already connected to a network:}{31} \contentsline {subsubsection}{Risks and Irregularities}{32} \contentsline {subsection}{\numberline {2.4.2}Law Situation in Germany}{32} \contentsline {chapter}{\numberline {3}IMSI Catcher Detection}{35} \contentsline {section}{\numberline {3.1}Framework and Hardware}{35} \contentsline {subsection}{\numberline {3.1.1}OsmocomBB}{35} \contentsline {subsubsection}{Project Status}{36} \contentsline {subsection}{\numberline {3.1.2}Motorola C123}{37} \contentsline {subsection}{\numberline {3.1.3}OsmocomBB and ICDS}{38} \contentsline {section}{\numberline {3.2}Procedure}{39} \contentsline {subsection}{\numberline {3.2.1}Information Gathering}{39} \contentsline {subsection}{\numberline {3.2.2}Information Evaluation}{42} \contentsline {subsubsection}{Neighbourhood Structure}{44} \contentsline {subsubsection}{Base Station Evaluation}{45} \contentsline {subsection}{\numberline {3.2.3}Forged Parameters}{47} \contentsline {subsubsection}{Database Rules}{48} \contentsline {subsubsection}{Remaining Issues and Paging}{49} \contentsline {section}{\numberline {3.3}IMSI Catcher Detection System}{50} \contentsline {subsection}{\numberline {3.3.1}Implemetation}{50} \contentsline {subsection}{\numberline {3.3.2}Configuration}{51} \contentsline {subsection}{\numberline {3.3.3}Operation}{52} \contentsline {paragraph}{Sweep scans:}{55} \contentsline {paragraph}{CellID Information:}{55} \contentsline {paragraph}{Location Area Database:}{57} \contentsline {paragraph}{PCH Scan:}{57} \contentsline {paragraph}{User Mode:}{57} \contentsline {section}{\numberline {3.4}Related Projects}{58} \contentsline {chapter}{\numberline {4}Evaluation}{61} \contentsline {section}{\numberline {4.1}Performance Evaluation}{61} \contentsline {subsection}{\numberline {4.1.1}Scan Duration}{62} \contentsline {subsection}{\numberline {4.1.2}Cell ID Databases}{63} \contentsline {subsection}{\numberline {4.1.3}PCH Scan Speed}{63} \contentsline {section}{\numberline {4.2}IMSI Catcher Detection}{63} \contentsline {subsection}{\numberline {4.2.1}Open Source IMSI Catcher}{64} \contentsline {subsubsection}{Nokia 3310}{65} \contentsline {subsection}{\numberline {4.2.2}Rule Evaluation}{66} \contentsline {subsection}{\numberline {4.2.3}Long Term Test}{67} \contentsline {subsection}{\numberline {4.2.4}Attack Scenarios}{68} \contentsline {chapter}{\numberline {5}Conclusion}{71} \contentsline {section}{\numberline {5.1}Future Work}{71} \contentsline {chapter}{Bibliography}{73} \contentsline {chapter}{\numberline {A}OsmocomBB}{77} \contentsline {section}{\numberline {A.1}Installation}{77} \contentsline {section}{\numberline {A.2}Usage}{78} \contentsline {section}{\numberline {A.3}Serial Cable Schematics}{79} \contentsline {chapter}{\numberline {B}IMSI Catcher Detection System}{81} \contentsline {section}{\numberline {B.1}Extextions}{81} \contentsline {section}{\numberline {B.2}Example Configuration}{82} \contentsline {chapter}{\numberline {C}System Information}{85} \contentsline {chapter}{\numberline {D}Evaluation Data}{91} \contentsline {section}{\numberline {D.1}IMSI Catcher Configurations}{91} \contentsline {chapter}{Acronyms}{93}