\chapter*{Abstract} \adjustmtc \addcontentsline{toc}{chapter}{Abstract} %Through advancements in cryptography, nowadays it is feasible to construct networked computer systems that for all %intents and purposes cannot be hacked over the network. Correctly applying cryptographic protocols and techniques such %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 more fundamental security guarantees. System-level tamper protection is sometimes used, but remains relegated to niche applications due to the high cost and low performance of devices like Hardware Security Modules (HSMs). In this thesis, Jan Sebastian Götte introduces the Inertial Hardware Security Module (IHSM), a new architecture for low-cost hardware security modules that provide high-level active tamper protection, while supporting computing payloads of much larger size, weight and power dissipation compared to conventional HSMs. In an IHSM, the costly and difficult to 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. 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. 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, nodes are distributed across data centers to avoid a single point of failure for physical attacks. As a result, practical MPC deployments are limited by network bandwidth and latency constraints. Using IHSMs, physically secured MPC nodes can be deployed within the same data center, increasing bandwidth, reducing latency and unlocking a new performance spectrum.