\documentclass[naustrian,notes,aspectratio=169]{beamer}

\input{header}
%Titelinformationen
\title[Digidow Biometric Sensor]{Digital Shadow: Biometric Sensor}
\subtitle{Master's Thesis Seminar}
\author[Michael Preisach]{Michael Preisach}
\date{April 21, 2020}
\institute[INS]{\includegraphics[width=0.1\textwidth]{../../resources/ins}}

\begin{document}
\begin{frame}
	\titlepage
\end{frame}
	
\begin{frame}
	\frametitle{Biometric Sensor as Part of Digidow}
	\begin{figure}
		\centering
		\includegraphics[width=0.7\textwidth]{../../resources/globalview}
	\end{figure}
\end{frame}

\begin{frame}
	\frametitle{Threat Model}
	\begin{itemize}
		\item Biometric Sensor (BS) point of view
		\begin{itemize}
			\item Rogue Personal Identity Agent (PIA)
			\item Metadata/Attribute Extraction on Network
			\item Defects on Network - Discovery not working 
			\item Sensor data modification at sensor hardware (e.\,g. camera)
			\item Physical manipulation of hardware
		\end{itemize}
		\item Network/PIA point of view
		\begin{itemize}
			\item Retransmission of sensor data
			\item Blocking data transmission
			\item Sensor data aggregation
			\item Sensor data modification before transmission
		\end{itemize}
	\end{itemize}
\end{frame}

\begin{frame}
	\frametitle{Trusted Platform Module (TPM)}
	\begin{columns}
		\begin{column}{0.55\textwidth}
			\begin{itemize}
				\item Dedicated Cryptocoprocessor in the PC
				\item Toolset available for measurement, attestation, key management, \ldots
				\item Available Hierarchies: Storage, Endorsement, Platform, Null
				\item Platform Configuration Registers (PCR) for the state of the system\footnotemark
			\end{itemize}
		\end{column}
		\begin{column}{0.45\textwidth}  %%<--- here
			\begin{footnotesize}
				\begin{tabular}{c|l}
					PCR &Usage\\\hline
					0	&UEFI boot and runtime services			\\
					1	&SMBIOS, ACPI, \ldots	\\
					4	&UEFI OS Loader			\\
					5	&ESP, GPT		\\
					7	&Unified Kernel\\
					10	&Integrity Measurements (by Kernel)\\
				\end{tabular}   
			\end{footnotesize}
		\end{column}
	\end{columns}
	\footnotetext{\url{https://www.trustedcomputinggroup.org/wp-content/uploads/PC-ClientSpecific_Platform_Profile_for_TPM_2p0_Systems_v21.pdf}}
\end{frame}

\begin{frame}
	\frametitle{Integrity Measurement Architecture\footnote{\url{https://wiki.gentoo.org/wiki/Integrity_Measurement_Architecture}}}
	\begin{itemize}
		\item Compile options within the Linux Kernel
		\item When the Kernel starts, a large set of resources can be measured
		\begin{itemize}
			\item files accessed by root
			\item all executables run
			\item shared libs and all other files held in memory
			\item \ldots
		\end{itemize}
		\item Based on policies, cooperates with selinux
		\item Creates Hash chain in PCR 10 (default)
		\begin{itemize}
			\item new\_hash = hash(old\_hash | resource)
		\end{itemize}
		\item integrity log lists measured resources, different file formats possible
		\item Attestation
		\begin{enumerate}
			\item Create Attestation Identity Key (AIK) from the Endorsement Key
			\item Sign the current PCR value and the log with the AIK
		\end{enumerate}
	\end{itemize}
\end{frame}

\begin{frame}
	\frametitle{TPM environment for DAA}
	\begin{figure}
		\centering
		\includegraphics[width=0.8\textwidth]{../../resources/tpmkeys}
	\end{figure}
	
	\begin{itemize}
		\item TPM can sign messages with the AIK
		\item The signature is proofable with the Issuer Public Key (zero knowledge proof)
	\end{itemize}
\end{frame}

\begin{frame}
	\frametitle{DAA Verification}
	\begin{columns}
	\begin{column}{0.55\textwidth}
		\begin{figure}
			\centering
			\includegraphics[width=\textwidth]{../../resources/tpmattest}
		\end{figure}
	\end{column}
	\begin{column}{0.45\textwidth}  %%<--- here
		\begin{itemize}
			\item Issuer Public Key is assumed known to any PIA
			\item Verifier (PIA) can only check validity of BS
			\item Only communication between PIA and BS
			\item Revocation lists manage termination of subscription
		\end{itemize}
	\end{column}
\end{columns}
\end{frame}

\begin{frame}
	\frametitle{Mitigated Threats}
	\begin{itemize}
		\item Biometric Sensor point of view
		\begin{itemize}
			\item Rogue PIA \textcolor{orange}{Two way DAA? TBD}
			\item Metadata/Attribute Extraction on Network \textcolor{orange}{Cert based channel encryption? TBD}
			\item Defects on Network - Discovery not working \textcolor{red}{Denial of Service}
			\item Sensor data modification at sensor hardware \textcolor{green}{Firmware/Driver trust/attestation}
			\item Physical manipulation of hardware \textcolor{orange}{Trusted Bootchain}
		\end{itemize}
		\item Network/PIA point of view
		\begin{itemize}
			\item Retransmission of sensor data \textcolor{green}{Integrity Measurement/Trusted Software}
			\item Blocking data transmission \textcolor{green}{Integrity Measurement/Trusted Software}
			\item Sensor data aggregation \textcolor{green}{Integrity Measurement/Trusted Software}
			\item Sensor data modification before transmission \textcolor{green}{Integrity Measurement/Trusted Software}
		\end{itemize}
	\end{itemize}
\end{frame}

\begin{frame}
	\frametitle{State of the project}
	\begin{itemize}
		\item Trusted Boot: ready, different flavors tested
		\item DAA: Basically working, Attestation Key not yet in TPM
		\item Integrity Measurement: ongoing, not running, policy design necessary
		\item Put above parts together
		\item Thesis: Theoretical concepts need to be written down
		\item Future work: minimize system, hardening on OS level
	\end{itemize}
\end{frame}

\end{document}
