Include first of leo's notes

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%as formal verification, it can be ensured that a software implementation is a flawless representation of its theoretical
%model, and that the theoretical model is secure given universally accepted cryptographic assumptions. Despite
% FIXME leo's notes
With cryptographic advancements and techniques like formal verification leading to increasingly secure software, the
hardware level advances into the focus of contemporary applied computer security research. However, the state of the art
in hardware security still often relies on the use of microelectronic integration to achieve security by obscurity over
@ -20,16 +21,21 @@ of much larger size, weight and power dissipation compared to conventional HSMs.
source tamper-sensing mesh of a conventional HSM is replaced by a mesh made from simple PCBs that is rotating at high
speed around the payload. Since the mesh is rotating, it cannot be manipulated, and the security of conventional meshes
created in bespoke manufacturing processes can be achieved using much simpler and less expensive construction
techniques. The thesis presents solutions to key engineering challenges in IHSM construction including a highly
symmetric planar inductor design for rotating wireless power transfer and a high-fidelity monitoring system for low-cost
security meshes.
techniques. We present the results of a survey of approximately 30 real world tamper sensing mesh implementations. We
deduce design criteria for secure meshes and contextualize our design. We further motivate the necessity of secure
hardware by presenting an analysis of problematic aspects in the hardware security design of Germany's new national
electronic health record system.
Applying IHSM technology, the thesis concludes with analyses of two use cases that are unlocked by the increased
size and power dissipation capability of IHSMs. In the first analysis, an IHSM-secured relay node for Quantum Key
Distribution (QKD) systems is proposed, enabling their practical implementation across arbitrary distances, which
requires trusted relay stations due to fundamental physical limitations. In the study, IHSMs are adapted for such
high-security QKD relays by securing the IHSM mesh passthrough with a secondary tamper-sensing mesh. In this setup, a
bracket design is proposed that supports passing through optical fibers at low loss.
To pave the way for practical implementations of IHSM technology, we present solutions to key engineering challenges in
IHSM construction including a highly symmetric planar inductor design for rotating wireless power transfer and a
high-fidelity monitoring system for low-cost security meshes.
Applying IHSM technology, we analyse two use cases that are unlocked by the increased size and power dissipation
capability of IHSMs. In the first analysis, an IHSM-secured relay node for Quantum Key Distribution (QKD) systems is
proposed, enabling their practical implementation across arbitrary distances, which requires trusted relay stations due
to fundamental physical limitations. In the study, IHSMs are adapted for such high-security QKD relays by securing the
IHSM mesh passthrough with a secondary tamper-sensing mesh. In this setup, a bracket design is proposed that supports
passing through optical fibers at low loss.
The second proposed use case adapts an IHSM enclosure to the size, power and thermal dissipation requirements of a
high-power server to support co-located secure Multiparty Computation (MPC) workloads. In practical MPC deployments,

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@ -6,25 +6,26 @@
This thesis has been written during the years of 2020 - 2025. In this time, Artificial Intelligence (AI) technology
including Large Language Models (LLMs) has entered widespread adoption. I have used such LLM systems in the preparation
of this thesis. At the time this thesis was written, LLMs were a powerful and useful technology, but often produced
wrong output. Thus, I used the following list of observations to guide my LLM use during the writing of this thesis.
wrong output. Thus I used the following list of observations to guide my LLM use during the writing of this thesis.
\begin{enumerate}
\item Passing text through an LLM is an imprecise operation. Especially when large amounts of text are passed
through an LLM, despite clear instructions such as ``only fix spelling errors,'' the LLM output might deviate
from the source text. Therefore, the document text should never be passed through the LLM, and the LLM should be
prompted to point out problems, or to produce a list of suggestions for improvements instead.
\item LLMs are really bad at summarizing text that contains novel concepts. LLM summaries of text often converge to
a re-stating of the general consensus on the text's main topic. Where the source text deviates from conventional
wisdom or makes novel points, an LLM summary will likely mis-represent those conclusions. Additionally, LLMs are
bad at capturing the point of a text. Unless extreme care is taken when prompting, it is easy to lead an LLM to
produce an inaccurate summary of a text that agrees with the prompt, but misses the gist of the text. Therefore,
extreme caution should be applied when using an LLM for summarization, and LLM output should be checked
diligently in such instances.
\item LLMs are bad at generating text from scratch. Especially on topics of academic interest that are novel and
that do not have well-known answers that can be found in the training corpus for these models, in general they
will not produce useful text when prompted. Therefore, LLMs should never be used to generate novel text.
\item LLMs are really bad at giving references. Prompts that ask for academic references on a topic are likely to
produce non-existing ``hallucinated'' references. The existing references an LLM is most likely to dig up
\item Contemporary LLMs are bad at summarizing text that contains novel concepts. LLM summaries of text often
converge to a re-stating of the general consensus on the text's main topic. Where the source text deviates from
conventional wisdom or makes novel points, an LLM summary will likely mis-represent those conclusions.
Additionally, LLMs are bad at capturing the point of a text. Unless extreme care is taken when prompting, it is
easy to lead an LLM to produce an inaccurate summary of a text that agrees with the prompt, but misses the gist
of the text. Therefore, extreme caution should be applied when using an LLM for summarization, and LLM output
should be checked diligently in such instances.
\item Contemporary LLMs are bad at generating text from scratch. Especially on topics of academic interest that are
novel and that do not have well-known answers that can be found in the training corpus for these models, in
general they will not produce useful text when prompted. Therefore, LLMs should never be used to generate novel
text.
\item Contemporary LLMs are bad at giving references. Prompts that ask for academic references on a topic are likely
to produce non-existing ``hallucinated'' references. The existing references an LLM is most likely to dig up
usually occur on the first page of a web search on the topic, or are frequently cited in literature on the
topic. Thus, LLMs should never be directly queried for references. When researching a new concept, a better use
of an LLM is the generation of query strings for search engines like Google Scholar.

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@ -34,15 +34,6 @@
% designs, code and data as open source to create the groundwork for future research, and sow the seeds for a new
% generation of secure hardware that will be able to resist a rising tide of fascist and authoritarian movements.
%
%
%
% Research questions:
% 1. can hsm w/o proprietary mesh?
% 2. how do meshes look like in practice?
% 3. can we improve monitoring?
% 4. can we solve power transfer issue
% 5. applications
%
\emph{No Gods, No Masters} is an anarchist slogan originating in the 19\textsuperscript{th} century that expresses a
rejection of authorities~\cite{broussaisOriginesDeviseAnarchiste2022,guerinNoGodsNo2005,blomNoGodsNo2025}. In modern
@ -86,7 +77,9 @@ systems are still routinely compromised~\cite{
goldmanUnrestrainedChineseCyberattackers2025,
scott-railtonWhoseAuthorityPegasus2024,
quintinSomethingRememberUs2024,
marczakGraphiteCaughtFirst2025}.
marczakGraphiteCaughtFirst2025,
PredatorFilesTechnical2023,
PakistanMassSurveillance2025}.
A fundamental flaw of any practical cryptographic system is that secure algorithms have to run on hardware, and even
today, average computing hardware provides little physical security~\cite{
gotzfriedCacheAttacksIntel2017,
@ -128,30 +121,39 @@ cryptographic engineering is Kerckhoffs' principle\footnote{
as well as a translation of the cited part from French. The original source is
\textcite{kerckhoffsCryptographieMilitaire1883}.
}, named after Dutch military cryptographer Auguste Kerckhoffs. Kerckhoffs' principle expresses that the security of a
cryptographic system should only depend on the secrecy of its keys, not on the secrecy of its design. In this way,
Kerckhoff's principle states the opposite of the widespread industry practice of \emph{Security by Obscurity}, which
aims to achieve security by making it sufficiently costly to cryptoanalyze a system that the attempt becomes
unattractive. All existing commercial HSM designs as well as some existing academic related work violate this principle
by keeping details of their implementation such as the precise mesh dimensions and manufacturing methods secret. By
publishing all details of our research into HSMs and their components, we provide the foundation for future independent
research.
cryptographic system should only depend on the secrecy of its keys, not on the secrecy of its design. Existing
commercial designs routinely contravene Kerckhoff's principle by applying the widespread industry practice of
\emph{Security by Obscurity}. Even in academic related work, the principle is sometimes violated by omitting
implementation and methodological details in the interest of patents and commercial exploitation. By publishing all
details of our research into HSMs and their components, we provide the foundation for future independent research.
Complementary to Kerckhoff's principle is the principle of least authority, which describes that in a secure system each
component should only have access to the smallest set of capabilities necessary to fulfill its purpose. Applying both to
a cryptographic system means that the system's design should be transparent and not include any hidden components or
opaque parts that cannot be inspected, and that the system's keys should be scoped to place the least amount of trust
possible in each participating party. Existing HSMs are an example of a violation of the principle of least authority
since they elevate the HSM manufacturer to a single point of failure. The tamper sensing mesh foils used in conventional
HSMs are made in proprietary, bespoke processes, and cannot be manufactured independently. Our proposed design can be
replicated from standard components and eliminates this issue.
Beyond applying Kerckhoffs' principle, publishing our design also enables independent replication. Our design is
based entirely on standard components and does not require bespoke manufacturing processes. Both commercial and academic
existing HSM tamper sensing designs require bespoke manufacturing methods or custom integrated circuits
(ICs)~\cite{
obermaierPUFfilmMethodProducing2023,
immler2019,
garbTamperSensitiveDesignPUFBased,
immlerBTREPIDBatterylessTamperresistant2018}.
This creates a single point of failure in the manufacturer, and opens up an opportunity for a hardware supply-chain
attack~\cite{harrisonSoKSecurityArchitects2025}. Such supply chain attacks can be mitigated by independently
manufacturing our design.
\section{Research Questions and Contributions}
Based on the current state of the field of hardware security, we deduce three overarching research questions for this
thesis that progress from theory to practical deployment.
% Research questions:
% 1. can hsm w/o proprietary mesh?
% 2. how do meshes look like in practice?
% 3. can we improve monitoring?
% 4. can we solve power transfer issue
% 5. applications
%
\begin{enumerate}
\item Can we achieve physical security without relying on conventional tamper-sensing meshes?
\item Can we achieve physical security without relying on a conventional tamper-sensing meshes that requires a
bespoke manufacturing process?
\item Can we monitor tamper-sensing meshes at a higher detail level than the state of the art of a single, scalar
measurement?
\item Can we create the support components necessary to integrate a system that provides a practical security

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@ -29,13 +29,13 @@ draw a distinction in its terminology between the two classes.
\section{Use in government standards}
Under US national standard FIPS 140 in in its 2002 version
Under the still widely used US national standard FIPS 140 in in its 2002 version
2~\cite{usnationalinstituteofstandardsandtechnologySecurityRequirementsCryptographic2002}, a HSM would be called a
\emph{Multiple-Chip Cryptographic Module} that conforms to the standard's \emph{Security Level 4}. Interesting to note
are that only security level 4 requires any active tamper detection and response, so its security levels 3 and below do
not align with our HSM definition. Futher of note is that according to the standard, a single-chip solution does not
require any tamper detection and response either to meet the standard's security level 4, which is in misalignment with
our definition. The standard's 2019 updated version FIPS
\emph{Multiple-Chip Cryptographic Module} that conforms to the standard's \emph{Security Level} 4 out of 4. Interesting
to note are that only level 4 requires any active tamper detection and response, so devices compliant only up to levels
3 and below do not align with our HSM definition. Futher of note is that according to the standard, a single-chip
solution does not require any tamper detection and response either to meet the standard's security level 4, which is in
misalignment with our definition. The standard's 2019 updated version FIPS
140-3~\cite{usnationalinstituteofstandardsandtechnologySecurityRequirementsCryptographic2019} defers to the
international standards ISO/IEC 19790 and 24759.
@ -49,17 +49,17 @@ The Payment Card Industry Security Standards Council (PCI SSC) is an association
defines standards for all layers of card payment processing, from card payment terminals in stores to the handling of
payment data in online shop backend systems.
PCI SSC terminology aligns with our use and with common everyday use of the term HSM. In PCI SSC terminology, a HSM is a
crytographic device that has active tamper detecion and response circuitry. However, PCI SSC terminology differs from
our use of the term HSM in one nuance: In PCI SSC terminology, a HSM is specifically a datacenter device used for
backend processing of payment data. The general class of ``hardware devices performing some security function with or
without particular physical security requirements'' that ISO/IEC 19790 and other standards call a \emph{Hardware
PCI SSC terminology aligns with our definition and with common everyday use of the term HSM. In PCI SSC terminology, a
HSM is a crytographic device that has active tamper detecion and response circuitry. However, PCI SSC terminology
differs from our use of the term HSM in one nuance: In PCI SSC terminology, a HSM is specifically a datacenter device
used for backend processing of payment data. The general class of ``hardware devices performing some security function
with or without particular physical security requirements'' that ISO/IEC 19790 and other standards call a \emph{Hardware
Cryptographic Module}, in PCI SSC terminology is termed \emph{Secure Cryptographic Device (SCD)} in more recent standard
versions, which was updated from the previous term \emph{Tamper-Resistant Security Module (TRSM)}. Other than HSMs, PCI
SSC includes smartcards and card payment terminals in this category. Card payment terminals, referred to as
\emph{Pin-Entry Device (PED)} in PCI SSC standards, have to include a surprising amount of active tamper detection and
response functionality including partial coverage of areas like they system's main cryptographic processor and smart
card reader by battery-backed tamper-sensing meshes.
response functionality including partial coverage of areas like their main cryptographic processor and smart card reader
by battery-backed tamper-sensing meshes. Under our definition, these devices can be classified as a type of HSM.
\section*{Tamper-Sensing Meshes}
\addcontentsline{toc}{subsection}{Tamper-Sensing Meshes}
@ -71,4 +71,7 @@ less clear to people unfamiliar with the matter. It is also polysemous, and depe
or stamped metal meshes used as fences or as screens in front of windows to prevent break-ins. As a result, it is harder
to use in online searches, and when using Large Language Models (LLMs), it frequently leads to amusing hallucinations.
% FIXME note leo: Das ganze wirkt wie ein guter baustein für eine Einleitung. Für einen Terminologie übersicht ist es
% ansonsten auch eigentlich zu lang.
% Splitte das vielleicht auf, ein paar mehr details in den Abstract um die HSM definition etwas zu präzisieren, den rest
% in die Intro?

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@ -2893,6 +2893,19 @@
langid = {english}
}
@inproceedings{harrisonSoKSecurityArchitects2025,
title = {{{SoK}}: {{A Security Architect}}'s {{View}} of {{Printed Circuit Board Attacks}}},
shorttitle = {{{SoK}}},
author = {Harrison, Jacob and Jessurun, Nathan and Tehranipoor, Mark},
date = {2025},
pages = {1907--1924},
url = {https://www.usenix.org/conference/usenixsecurity25/presentation/harrison},
urldate = {2025-11-27},
eventtitle = {34th {{USENIX Security Symposium}} ({{USENIX Security}} 25)},
isbn = {978-1-939133-52-6},
langid = {english}
}
@inproceedings{hastingsSoKGeneralPurpose2019,
title = {{{SoK}}: {{General Purpose Compilers}} for {{Secure Multi-Party Computation}}},
shorttitle = {{{SoK}}},

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@ -8,6 +8,7 @@
\newcommand{\chaptertitle}[1]{
\chapter{#1}
\printchapterquote
%FIXME note leo: remove minitocs?
\begin{spacing}{1.1}
\minitoc
\end{spacing}
@ -34,8 +35,8 @@
\clearpage
\tableofcontents
\listoffigures
\listoftables
%\listoffigures
%\listoftables
\mainmatter
\dochapter{chapter-introduction} % Status: In pretty good shape