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QKD IWP

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chapter-qkd/chapter.tex
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@ -86,7 +86,11 @@
\pagestyle{fancy}
\fancyhead[C]{}
\fancyhead[ER]{\footnotesize\leftmark}
\fancyhead[ER]{\footnotesize%
\ifdefined\thesispreviewmode %
(draft \texttt{\input{version.tex}\unskip}) %
\fi %
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\fancyhead[OL]{\footnotesize\rightmark}
\fancyhead[EL,OR]{\thepage}
@ -146,8 +150,8 @@
(\underline{\href{\resourceurl}{link}})%
}
\newcommand{\draftgraphics}{\textcolor{red}{\bfseries Not final graphics;}}
\newcommand{\camerareadygraphics}{Camera-ready graphics;}
\newcommand{\draftgraphics}{\ifdefined\thesispreviewmode\textcolor{red}{\bfseries Not final graphics. }\fi}
\newcommand{\camerareadygraphics}{\ifdefined\thesispreviewmode Camera-ready graphics. \fi}
\newcommand{\scaledgraphics}[1]{\ifdefined\thesispreviewmode scaled-#1\else#1\fi}
\hyphenation{a-me-na-ble}
@ -157,6 +161,9 @@
\faketableofcontents
\chapter{Physical Security in Quantum Key Distribution}
\ifdefined\thesispreviewmode
{\Large \textbf{Draft build}, git revision \texttt{\input{version.tex}}}
\fi
\minitoc
\newpage
\setstretch{1.3}
@ -631,8 +638,12 @@ interlocking gear mesh.
\begin{figure}[h!]
\centering
\includegraphics[width=\textwidth,page=1]{shaft_countermeasures_b.pdf}
\caption[Coaxial disc mesh schema, top-down view]{Coaxial disc mesh schema, top-down view}
\caption[Coaxial disc mesh schema]{\draftgraphics Coaxial disc mesh schema, cross-section and top-down views. The
outer mesh is shown in red, and the inner mesh in blue. The dashed line indicates the two meshes' shared axis of
rotation. The gray areas indicate the shape of the volume that remains undisturbed by the mesh, and that is
available for structural support and cable routing.}
\end{figure}
\todo{Update these graphics with final color scheme, and update caption text here}
In Chapter \todoplaceholder{Provide link to single-board IHSM chapter here}, we have shown how an IHSM that has been
shrunk to a single, disc-shaped PCB is still useful because we can delegate key management functionality to the mesh
@ -644,13 +655,14 @@ implementation.
By placing an adapted single-board IHSM close to the primary mesh's axis opening, an attacker is forced to either first
circumvent the single-board IHSM through the primary mesh's axis opening, then remove enough of it to gain direct access
ot the payload behind it, or to conduct their attack while bending their tool by approximately \qty{90}{\degree} at
least twice, once to avoid the SB-IHSM mesh, and once more to re-orient the tool towards the payload. The distance
between the inside of the primary mesh and the SB-IHSM is limited by the tolerance in mechanical alignment between the
two axes of rotation, by the space necessary for a sufficiently stable mount of the payload cage to the hollow shaft,
and by the minimum bend radius of the power and data wiring that needs to pass through the shaft. In QKD applications,
the fibers' minimum bend radius is the largest contributor with a minimum distance of \qty{10}{\milli\meter}, equal to
the minimum bend radius specification that is common in telecom fiber optics.\todo{cite bend radius spec}
ot the payload behind it, or to conduct their attack through the keyhole-sized opening in the primary mesh while bending
their tool by approximately \qty{90}{\degree} at least twice, once to avoid the SB-IHSM mesh, and once more to re-orient
the tool towards the payload. The distance between the inside of the primary mesh and the SB-IHSM is limited by the
tolerance in mechanical alignment between the two axes of rotation, by the space necessary for a sufficiently stable
mount of the payload cage to the hollow shaft, and by the minimum bend radius of the power and data wiring that needs to
pass through the shaft. In QKD applications, the fibers' minimum bend radius is the largest contributor with a minimum
distance of \qty{10}{\milli\meter} that corresponds to the minimum bend radius specification that is common in telecom
fiber optics.\todo{cite bend radius spec}
\todoplaceholder{Finish this part.}
@ -658,16 +670,32 @@ the minimum bend radius specification that is common in telecom fiber optics.\to
\begin{figure}[h!]
\centering
\includegraphics[width=\textwidth,page=2]{shaft_countermeasures_b.pdf}
\caption[Coaxial labyrinth mesh schema, top-down view]{Coaxial labyrinth mesh schema, top-down view}
\includegraphics[width=\textwidth,page=4]{shaft_countermeasures_b.pdf}
\caption[Coaxial labyrinth mesh schema]{\draftgraphics Coaxial labyrinth mesh schema, cross-section and top-down
views.}
\end{figure}
To increase the difficulty of inserting a long and flexible tool through the axis shield, \todo{Axis shield might be a
nice term. Unify terminology for axis/shaft, the shield, the names of the two meshes, and the tabs sticking up from the
meshes. Also what do we call the space in between? Terminology for the sides with offset meshes?} the shape of the
interface layer between the two meshes can be made more complex. By introducing small mesh \emph{tabs} that stick out
into the inter-mesh space from both meshes, creating a labyrinth-like structure that requires structural support and
cables to pass in a series of \qty{90}{\degree} bends.
Designing this type of labyrinth mesh is similar to the design of the shape of the jamb of a safe door or of a high-end
european-style apartment door, where the objective is to prevent would-be burglars from inserting opening tools through
the space between the closed door and its jamb and attacking the door's interior handle. \todo{some pics would be nice
here}
\subsection{Offset labyrinth meshes}
\begin{figure}[h!]
\centering
\includegraphics[width=\textwidth,page=3]{shaft_countermeasures_b.pdf}
\caption[Offset labyrinth mesh schema, top-down view]{Offset labyrinth mesh schema, top-down view}
\includegraphics[width=\textwidth,page=2]{shaft_countermeasures_b.pdf}
\caption[Offset labyrinth mesh schema]{\draftgraphics Offset labyrinth mesh schema, cross-section and top-down
views. The two dashed lines indicate the two meshes' offset axes of rotation, shifted in $x$ direction in both
views.}
\label{qkd_fig_offset_lab_schema}
\end{figure}
In QKD applications, the simple disc cover design shown above has two main limitations. First, the distance between the
@ -685,12 +713,33 @@ offset labyrinth's sharp corners, an optical fiber can not. Thus, instead of pas
the payload's fiber optic connections are passed through the labyrinth in a three-dimensional spiral shape, avoiding the
meshes while simultaneously maximizing the fibers' bend radii.
\begin{figure}
\centering
\includegraphics[width=\textwidth]{\scaledgraphics{render_exp_1.png}}
\caption[Offset labyrinth mesh assmbly exploded render]{\figureattrib{render_exp_1.png}}
\end{figure}
\begin{figure}
\centering
\includegraphics[width=\textwidth]{\scaledgraphics{render_exp_2.png}}
\caption[Offset labyrinth mesh assmbly exploded render]{\figureattrib{render_exp_2.png}}
\end{figure}
\begin{figure}
\centering
\includegraphics[width=\textwidth]{example-image-10x16.pdf}
\caption[Offset labyrinth mesh assmbly exploded render, section view]{\draftgraphics\\
Section view of the labyrinth mesh assembly}
\end{figure}
\subsection{Interlocking gear meshes}
\begin{figure}[h!]
\centering
\includegraphics[width=\textwidth,page=4]{shaft_countermeasures_b.pdf}
\caption[Offset gear labyrinth mesh schema, top-down view]{Offset gear labyrinth mesh schema, top-down view}
\includegraphics[width=\textwidth,page=3]{shaft_countermeasures_b.pdf}
\caption[Offset gear labyrinth mesh schema]{\draftgraphics Offset gear labyrinth mesh schema, cross-section and
top-down views. In this example, the axis is shifted by about twice the offset from the previous offset labyrinth
mesh schema in Figure\ \ref{qkd_fig_offset_lab_schema}.}
\end{figure}
The offset labyrinth design already achieves a high level of security through its complex passthrough shape, but its
@ -720,25 +769,6 @@ meshes do not have to rotate at the same rate of rotation. Instead, harmonic rat
}
\end{figure}
\begin{figure}
\centering
\includegraphics[width=\textwidth]{\scaledgraphics{render_exp_1.png}}
\caption[Offset labyrinth mesh assmbly exploded render]{\figureattrib{render_exp_1.png}}
\end{figure}
\begin{figure}
\centering
\includegraphics[width=\textwidth]{\scaledgraphics{render_exp_2.png}}
\caption[Offset labyrinth mesh assmbly exploded render]{\figureattrib{render_exp_2.png}}
\end{figure}
\begin{figure}
\centering
\includegraphics[width=\textwidth]{example-image-10x16.pdf}
\caption[Offset labyrinth mesh assmbly exploded render, section view]{\draftgraphics\\
Section view of the labyrinth mesh assembly}
\end{figure}
\begin{figure}
\centering
\includegraphics[width=\textwidth]{gear_plan_1.eps}