From 7d99a18c935659967b19051f999e3fc353720e56 Mon Sep 17 00:00:00 2001
From: Tom
Date: Sun, 10 Jun 2012 18:34:23 +0200
Subject: increased shininess

---
 Tex/Content/Conclusion.tex | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

(limited to 'Tex/Content/Conclusion.tex')

diff --git a/Tex/Content/Conclusion.tex b/Tex/Content/Conclusion.tex
index 4242cb4..8c27e18 100644
--- a/Tex/Content/Conclusion.tex
+++ b/Tex/Content/Conclusion.tex
@@ -4,7 +4,8 @@ The first section starts by reviewing what has been done while the second sectio
 
 \section{Summary}
 The aim of this project was to find ways of unveiling whether an IMSI catcher is being operated in the close perimeter or not.
-In other words to find out whether it is safe to initiate a phone call or not.
+In other words to find out if it is safe to connect to the GSM network.
+An unsafe environment could result in IMSI numbers being requested and saved by IMSI catchers or in phone calls being recorded.
 The main premise that distinguishes this project from other similar projects like the also  OsmocomBB based 'Catcher Catcher' is that the system is operating in a completely passive manner.
 Therefore it can only work on a limited amount of information, namely on information that is broadcasted on publicly available channels.
 The benefit this yields over other projects is that the IMSI Catcher Detection System itself is completely invisible to the IMSI catcher.
@@ -30,8 +31,8 @@ The results show that some IMSI catcher configurations can be uncovered by these
 In addition to this data broadcasted on the \gls{bcch}, reception levels and \glspl{lac} are also monitored over time to unveil attacks in which existing base stations are replaced by IMSI catchers.
 This leaves IMSI catchers that have a consistent configuration and blend well in their surroundings concerning the reception levels.
 They are also broadcasting the same \gls{lac} as the replaced base station, even if this means it could take a long time until the \gls{ms} announces itself.
-To handle this case the \gls{icds} can monitor the \gls{pch} of the base station in question to gather Paging Messages and \glspl{ia}.
-Since an IMSI catcher is not part of the provider's network no paging messages will be forwarded to the connected subscribers.
+To handle this case the \gls{icds} can monitor the \gls{pch} of the base station in question to gather Paging Messages and Immediate Assignments.
+Since an IMSI catcher is not part of the provider's network no Paging Messages will be forwarded to the connected subscribers.
 These findings have been confirmed with the experiments in Chapter 4 where different attack scenarios have been tested.
 In cases where the \gls{icds} was not able to uncover the IMSI catcher by rule evaluation the \gls{pch} scan yielded the desired result.
 It should be kept in mind that the evaluation has been done against a prototype IMSI catcher since data from a real IMSI catcher is not available.
@@ -45,7 +46,7 @@ If a \gls{bts} is replaced right after it has been scanned it can take up to sev
 That is the time that is needed to do a complete sweep scan.
 The \gls{icds} could be refined so that only base stations of a particular provider are monitored so the duration of sweep scans is cut down, this could also be done upon entering \emph{User Mode}.
 
-In case of the Open Source IMSI Catcher no Paging Messages were sent.
+In case of the Open Source IMSI-Catcher no Paging Messages were sent.
 However it would be possible for a catcher that is aware of this evaluation criterion to send fake Paging Messages to arbitrary \glspl{tmsi} to deceive the \gls{icds}.
 To face this the \gls{icds} could be extended.
 Since Paging Messages would be unreliable in such a case one would have to use \glspl{ia}.
@@ -53,7 +54,7 @@ The experiments have shown that this might increase scanning time on the \gls{pc
 An \gls{ia} sent to a subscriber contains the dedicated channel on which the conversation between the base station and the mobile phone is to continue.
 At this point the \gls{icds} already uses the information about dedicated channels to see whether frequency hopping is used or not.
 If an \gls{ia} is caught by the \gls{icds} one could follow on the assigned channel and catch the Cipher Mode Message.
-Since an IMSI catcher will disable encryption to tap into calls, the Cipher Mode Message would contain A5/0 as its encryption algorithm.
+Since an IMSI catcher will disable encryption to tap into calls, the Cipher Mode Message would contain A5/0 as its encryption algorithm instead of A5/1 which is used in Germany.
 This feature could be used to handle cases of fake Paging Messages or \glspl{ia}, however it would take longer to conduct the \gls{pch} scan.
 Another problem would be that it requires another subscriber that is connected to the IMSI catcher initiating a call.
 On the other hand a regular base station using encryption can also be verified this way.
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