diff --git a/4-requirements.tex b/4-requirements.tex
index b3cd61b..a32c3ff 100644
--- a/4-requirements.tex
+++ b/4-requirements.tex
@@ -14,9 +14,9 @@ Even if the installation of an update fails in the middle of reprogramming the d
 \subsubsection{}\label{req3}Firmware downloads should be performed over the same WiFi connection as used during normal operation.
 Fetching the firmware should be done side-by-side with operational traffic.
 
-\subsubsection{}\label{req4}The update process can happen over any untrusted wireless network or Internet connection without being vulnerable to attackers.
+\subsubsection{}\label{req4}The update process can happen over any untrusted wireless network or Internet connection and therefor must not being vulnerable to attackers.
 To prevent possible attackers from injecting malicious software into the embedded devices, a cryptographic signature mechanism must be implemented.
-New firmware only gets accepted by the device, if the cryptographic signature of the downloaded firmware image can be verified.
+New firmware only gets accepted by the device, iff the cryptographic signature of the downloaded firmware image can be verified.
 
 \subsubsection{}\label{req5}To reduce network load and aim for the maximum possible uptime of the device, the update process should only be done if a new firmware version is available.
 In contrast, on the release of new firmware, the roll-out to all devices should be performed as fast as possible.
@@ -30,4 +30,4 @@ As the device type is hardly coupled to the hardware and the software interacts
 
 \makeatletter
 \renewcommand{\@IEEEsectpunct}{:\ \,}
-\makeatother
\ No newline at end of file
+\makeatother
diff --git a/foo.tex b/5-concept.tex
similarity index 100%
rename from foo.tex
rename to 5-concept.tex
diff --git a/5-1-update_mechanism.tex b/6-1-update_mechanism.tex
similarity index 100%
rename from 5-1-update_mechanism.tex
rename to 6-1-update_mechanism.tex
diff --git a/5-2-multidevice_build_structure.tex b/6-2-multidevice_build_structure.tex
similarity index 100%
rename from 5-2-multidevice_build_structure.tex
rename to 6-2-multidevice_build_structure.tex
diff --git a/5-3-automatic-deployment.tex b/6-3-automatic-deployment.tex
similarity index 100%
rename from 5-3-automatic-deployment.tex
rename to 6-3-automatic-deployment.tex
diff --git a/5-implementation.tex b/6-implementation.tex
similarity index 85%
rename from 5-implementation.tex
rename to 6-implementation.tex
index 45fe9b2..1fbe0db 100644
--- a/5-implementation.tex
+++ b/6-implementation.tex
@@ -7,6 +7,6 @@ It is responsible for checking and downloading the updates and installing them.
 Second, the build system is in charge of building the firmware from source and publishing the built binary images.
 Finally, the deployment provides infrastructure for downloading the binary firmware images and triggering the update on all devices.
 
-\input{5-1-update_mechanism}
-\input{5-2-multidevice_build_structure}
-\input{5-3-automatic-deployment}
\ No newline at end of file
+\input{6-1-update_mechanism}
+\input{6-2-multidevice_build_structure}
+\input{6-3-automatic-deployment}
\ No newline at end of file
diff --git a/6-conclusion.tex b/7-conclusion.tex
similarity index 100%
rename from 6-conclusion.tex
rename to 7-conclusion.tex
diff --git a/esper-ota.tex b/esper-ota.tex
index 3f054dc..dd9ef25 100755
--- a/esper-ota.tex
+++ b/esper-ota.tex
@@ -465,9 +465,9 @@ Secure Updates, Over the Air, ESP8266.
 \input{2-related-work}
 \input{3-environment}
 \input{4-requirements}
-\input{foo}
-\input{5-implementation}
-\input{6-conclusion}
+\input{5-concept}
+\input{6-implementation}
+\input{7-conclusion}
 
 % ************************************