System on Wafer (SoW) based on chiplets may be implanted with hardware Trojans (HTs) by untrustworthy third‐party chiplet vendors. However, traditional HTs protection techniques cannot guarantee complete protection against HTs, which poses a great challenge to the hardware security of SoW. In this paper, we propose a computing architecture based on endogenous security theory—dynamic heterogeneous redundant computing architecture (DHRCA) that can tolerate and detect HTs at runtime. The security of our approach is analyzed by building a generalized stochastic coloring petri net (GSCPN) model of DHRCA. The simulation results based on the GSCPN model show that our method can improve the system security probability to 0.8690 and the system availability probability to 0.9750 in the steady state compared with typical triple‐mode redundancy and runtime monitoring methods. Furthermore, the impact of different attack and defense strategies on system security of different methods is simulated and analyzed in this paper.

Abstract At present, attacks based on the vulnerability of the controller and flooding attacks still constitute a principal threat for hierarchical Software Defined Network (SDN), such as flow table tampering, malicious Application attacks, Distributed Denial of Service (DDoS) etc., due to the limitation against attacks based on known or unknown vulnerabilities for traditional cyber defence technology. Therefore, this study proposes an active defence architecture based on Mimic Defence (MD)–Mimic Hierarchical SDN Framework (MHSDN). Then endogenous security of MHSDN is theoretically analysed. Simultaneously, the attack surface measurement of MD is innovatively proposed, further improving the security and usability measurement standards of the MD system. Finally, to speed up detection and reduce defence cost of DDoS, this research proposes the Random Forest Feature Extract (RFFE) and tolerable switch migration. Simulation shows that RFFE has achieved a faster detection speed at the cost of less detection accuracy, and MHSDN can better improve the reliability of hierarchical SDN.

Motion estimation is a fundamental step in dynamic medical image processing for the assessment of target organ anatomy and function. However, existing image-based motion estimation methods, which optimize the motion field by evaluating the local image similarity, are prone to produce implausible estimation, especially in the presence of large motion. In addition, the correct anatomical topology is difficult to be preserved as the image global context is not well incorporated into motion estimation. In this study, we provide a novel motion estimation framework of dense-sparse-dense (DSD), which comprises two stages. In the first stage, we process the raw dense image to extract sparse landmarks to represent the target organ's anatomical topology, and discard the redundant information that is unnecessary for motion estimation. For this purpose, we introduce an unsupervised 3-D landmark detection network to extract spatially sparse but representative landmarks for the target organ's motion estimation. In the second stage, we derive the sparse motion displacement from the extracted sparse landmarks of two images of different time points. Then, we present a motion reconstruction network to construct the motion field by projecting the sparse landmarks' displacement back into the dense image domain. Furthermore, we employ the estimated motion field from our two-stage DSD framework as initialization and boost the motion estimation quality in light-weight yet effective iterative optimization. We evaluate our method on two dynamic medical imaging tasks to model cardiac motion and lung respiratory motion, respectively. Our method has produced superior motion estimation accuracy compared to the existing comparative methods. Besides, the extensive experimental results demonstrate that our solution can extract well-representative anatomical landmarks without any requirement of manual annotation. Our code is publicly available online: https://github.com/yyguo-sjtu/DSD-3D-Unsupervised-Landmark-Detection-Based-Motion-Estimation.